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Pangeni R, Poudel S, Momin MAM, Farkas D, Dalton C, Hall F, Kang JD, Hylemon P, Longest W, Hindle M, Xu Q. Inhalable tobramycin EEG powder formulation for treating Pseudomonas aeruginosa-induced lung infection. Int J Pharm 2024; 662:124504. [PMID: 39053676 DOI: 10.1016/j.ijpharm.2024.124504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/01/2024] [Accepted: 07/20/2024] [Indexed: 07/27/2024]
Abstract
Pulmonary delivery of antibiotics is an effective strategy in treating bacterial lung infection for cystic fibrosis patients, by achieving high local drug concentrations and reducing overall systemic exposure compared to systemic administration. However, the inherent anatomical lung defense mechanisms, formulation characteristics, and drug-device combination determine the treatment efficacy of the aerosol delivery approach. In this study, we prepared a new tobramycin (Tobi) dry powder aerosol using excipient enhanced growth (EEG) technology and evaluated the in vitro and in vivo aerosol performance. We further established a Pseudomonas aeruginosa-induced lung infection rat model using an in-house designed novel liquid aerosolizer device. Notably, novel liquid aerosolizer yields comparable lung infection profiles despite administering 3-times lower P. aeruginosa CFU per rat in comparison to the conventional intratracheal administration. Dry powder insufflator (e.g. Penn-Century DP-4) to administer small powder masses to experimental animals is no longer commercially available. To address this gap, we developed a novel rat air-jet dry powder insufflator (Rat AJ DPI) that can emit 68-70 % of the loaded mass for 2 mg and 5 mg of Tobi-EEG powder formulations, achieving a high rat lung deposition efficiency of 79 % and 86 %, respectively. Rat AJ DPI can achieve homogenous distribution of Tobi EEG powder formulations at both loaded mass (2 mg and 5 mg) over all five lung lobes in rats. We then demonstrated that Tobi EEG formulation delivered by Rat AJ DPI can significantly decrease CFU counts in both trachea and lung lobes at 2 mg (p < 0.05) and 5 mg (p < 0.001) loaded mass compared to the untreated P. aeruginosa-infected group. Tobi EEG powder formulation delivered by the novel Rat AJ DPI showed excellent efficiencies in substantially reducing the P. aeruginosa-induced lung infection in rats.
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Affiliation(s)
- Rudra Pangeni
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Surendra Poudel
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Mohammad A M Momin
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Dale Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Caleb Dalton
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Felicia Hall
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Jason D Kang
- Division of Microbiology and Immunology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA; Stravitz-Sanyal Institute for Liver Disease & Metabolic Health, Virginia Commonwealth University, School of Medicine, Richmond, VA, USA
| | - Phillip Hylemon
- Division of Microbiology and Immunology, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA, USA
| | - Worth Longest
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA; Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Qingguo Xu
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA; Department of Ophthalmology, Massey Cancer Center, Center for Pharmaceutical Engineering, and Institute for Structural Biology, Drug Discovery & Development (ISB3D), Virginia Commonwealth University, Richmond, VA, USA.
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Aladwani G, Momin MAM, Spence B, Farkas DR, Bonasera S, Hassan A, Hindle M, Longest W. Effects of different mesh nebulizer sources on the dispersion of powder formulations produced with a new small-particle spray dryer. Int J Pharm 2023; 642:123138. [PMID: 37307962 PMCID: PMC10527815 DOI: 10.1016/j.ijpharm.2023.123138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/14/2023]
Abstract
The objective of this study was to explore the aerosolization performance of powders produced with different mesh nebulizer sources in the initial design of a new small-particle spray dryer system. An aqueous excipient enhanced growth (EEG) model formulation was spray dried using different mesh sources and the resulting powders were characterized based on (i) laser diffraction, (ii) aerosolization with a new infant air-jet dry powder inhaler, and (iii) aerosol transport through an infant nose-throat (NT) model ending with a tracheal filter. While few differences were observed among the powders, the medical-grade Aerogen Solo (with custom holder) and Aerogen Pro mesh sources were selected as lead candidates that produced mean fine particle fractions <5 µm and <1 µm in ranges of 80.6-77.4% and 13.1-16.0%, respectively. Improved aerosolization performance was achieved at a lower spray drying temperature. Lung delivery efficiencies through the NT model were in the range of 42.5-45.8% for powders from the Aerogen mesh sources, which were very similar to previous results with a commercial spray dryer. Ultimately, a custom spray dryer that can accept meshes with different characteristics (e.g., pore sizes and liquid flow rates) will provide particle engineers greater flexibility in producing highly dispersible powders with unique characteristics.
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Affiliation(s)
- Ghali Aladwani
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Mohammad A M Momin
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Benjamin Spence
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Amr Hassan
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States; Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States.
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Farkas D, Thomas ML, Hassan A, Bonasera S, Hindle M, Longest W. Near Elimination of In Vitro Predicted Extrathoracic Aerosol Deposition in Children Using a Spray-Dried Antibiotic Formulation and Pediatric Air-Jet DPI. Pharm Res 2023; 40:1193-1207. [PMID: 35761163 PMCID: PMC10616820 DOI: 10.1007/s11095-022-03316-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/10/2022] [Indexed: 10/17/2022]
Abstract
PURPOSE This study evaluated the in vitro aerosol performance of a dry powder antibiotic product that combined a highly dispersible tobramycin powder with a previously optimized pediatric air-jet dry powder inhaler (DPI) across a subject age range of 2-10 years. METHODS An excipient enhanced growth (EEG) formulation of the antibiotic tobramycin (Tobi) was prepared using a small particle spray drying technique that included mannitol as the hygroscopic excipient and trileucine as the dispersion enhancer. The Tobi-EEG formulation was aerosolized using a positive-pressure pediatric air-jet DPI that included a 3D rod array. Realistic in vitro experiments were conducted in representative airway models consistent with children in the age ranges of 2-3, 5-6 and 9-10 years using oral or nose-to-lung administration, non-humidified or humidified airway conditions, and constant or age-specific air volumes. RESULTS Across all conditions tested, mouth-throat depositional loss was < 1% and nose-throat depositional loss was < 3% of loaded dose. Lung delivery efficiency was in the range of 77.3-85.1% of loaded dose with minor variations based on subject age (~ 8% absolute difference), oral or nasal administration (< 2%), and delivered air volume (< 2%). Humidified airway conditions had an insignificant impact on extrathoracic depositional loss and significantly increased aerosol size at the exit of a representative lung chamber. CONCLUSIONS In conclusion, the inhaled antibiotic product nearly eliminated extrathoracic depositional loss, demonstrated high efficiency nose-to-lung antibiotic aerosol delivery in pediatric airway models for the first time, and provided ~ 80% lung delivery efficiency with little variability across subject age and administered air volume.
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Affiliation(s)
- Dale Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, Virginia, 23284-3015 , USA
| | - Morgan L Thomas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, Virginia, 23284-3015 , USA
| | - Amr Hassan
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, Virginia, 23284-3015 , USA.
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA.
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Pangeni R, Hassan AAM, Farkas D, Sudarjat H, Longest W, Hindle M, Xu Q. New Air-Jet Dry Powder Insufflator for High-Efficiency Aerosol Delivery to Rats. Mol Pharm 2023; 20:2207-2216. [PMID: 36938947 DOI: 10.1021/acs.molpharmaceut.3c00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Pulmonary deposition of lung-targeted therapeutic aerosols can achieve direct drug delivery to the site of action, thereby enhancing the efficacy and reducing systemic exposure. In this study, we investigated the in vitro and in vivo aerosol performance of the novel small animal air-jet dry powder insufflator (Rat AJ DPI) using spray-dried albuterol excipient-enhanced-growth (EEG) powder as a model formulation. The in vitro aerosolization performance of the optimized albuterol EEG powder was first assessed using the Rat AJ DPI. The performance of Rat AJ DPI to deliver albuterol EEG aerosol to rat lungs was then compared to that of the Penn-Century Insufflator. Albuterol EEG powders dispersed using the Rat AJ DPI demonstrated narrow unimodal aerosol size distribution profiles, which were independent of the loaded powder dose (1, 2, and 5 mg). In addition, the span value for Rat AJ DPI (5 mg powder mass) was 1.32, which was 4.2-fold lower than that for Penn-Century insufflator (5 mg powder mass). At a higher loaded mass of 5 mg, the Rat AJ DPI delivered significantly larger doses to rat lungs compared with the Penn-Century DPI. The Rat AJ DPI with hand actuation delivered approximately 85% of the total emitted dose (2 and 5 mg loadings), which was comparatively higher than that for Penn-Century DPI (approximately 75%). In addition, percentage deposition in each of the lung lobes for the Rat AJ DPI was observed to be independent of the administration dose (2 and 5 mg loadings) with coefficients of variation below 12%, except in the right middle lobe. Automatic actuation of a 5 mg powder mass using the Rat AJ DPI demonstrated a similar delivered dose compared to manual actuation of the same dose, with 82% of the total emitted dose reaching the lung lobes. High-efficiency delivery of the aerosol to the lobar lung region and low sensitivity of the interlobar delivery efficiency to the loaded dose highlight the suitability of the new air-jet DPI for administering therapeutic pharmaceutical aerosols to small test animals.
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Affiliation(s)
- Rudra Pangeni
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Amr Ali Mohamed Hassan
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Dale Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Hadi Sudarjat
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Worth Longest
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States.,Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States
| | - Qingguo Xu
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia 23298, United States.,Department of Ophthalmology, Massey Cancer Center, Center for Pharmaceutical Engineering, and Institute for Structural Biology, Drug Discovery & Development (ISB3D), Virginia Commonwealth University, Richmond, Virginia 23284, United States
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Pangeni R, Meng T, Poudel S, Sharma D, Hutsell H, Ma J, Rubin BK, Longest W, Hindle M, Xu Q. Airway mucus in pulmonary diseases: Muco-adhesive and muco-penetrating particles to overcome the airway mucus barriers. Int J Pharm 2023; 634:122661. [PMID: 36736964 PMCID: PMC9975059 DOI: 10.1016/j.ijpharm.2023.122661] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
Airway mucus is a complex viscoelastic gel that provides a defensive physical barrier and shields the airway epithelium by trapping inhaled foreign pathogens and facilitating their removal via mucociliary clearance (MCC). In patients with respiratory diseases, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), non-CF bronchiectasis, and asthma, an increase in crosslinking and physical entanglement of mucin polymers as well as mucus dehydration often alters and typically reduces mucus mesh network pore size, which reduces neutrophil migration, decreases pathogen capture, sustains bacterial infection, and accelerates lung function decline. Conventional aerosol particles containing hydrophobic drugs are rapidly captured and removed by MCC. Therefore, it is critical to design aerosol delivery systems with the appropriate size and surface chemistry that can improve drug retention and absorption with the goal of increased efficacy. Biodegradable muco-adhesive particles (MAPs) and muco-penetrating particles (MPPs) have been engineered to achieve effective pulmonary delivery and extend drug residence time in the lungs. MAPs can be used to target mucus as they get trapped in airway mucus by steric obstruction and/or adhesion. MPPs avoid muco-adhesion and are designed to have a particle size smaller than the mucus network, enhancing lung retention of particles as well as transport to the respiratory epithelial layer and drug absorption. In this review, we aim to provide insight into the composition of airway mucus, rheological characteristics of airway mucus in healthy and diseased subjects, the most recent techniques to study the flow dynamics and particle diffusion in airway mucus (in particular, multiple particle tracking, MPT), and the advancements in engineering MPPs that have contributed to improved airway mucus penetration, lung distribution, and retention.
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Affiliation(s)
- Rudra Pangeni
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Tuo Meng
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Sagun Poudel
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Divya Sharma
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| | - Hallie Hutsell
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Jonathan Ma
- Department of Pediatrics, Children's Hospital of Richmond, Richmond, VA, USA
| | - Bruce K Rubin
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, USA; Department of Pediatrics, Children's Hospital of Richmond, Richmond, VA, USA
| | - Worth Longest
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA; Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Qingguo Xu
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA; Department of Ophthalmology, Massey Cancer Center, Center for Pharmaceutical Engineering, and Institute for Structural Biology, Drug Discovery & Development (ISB3D), Virginia Commonwealth University, Richmond, VA, USA.
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Spence BM, Longest W, Dutta R, Momin MAM, Strickler S, Hindle M. In Vitro Evaluation of Nebulized Pharmaceutical Aerosol Delivery to the Lungs Using a New Heated Dryer System (HDS). AAPS PharmSciTech 2022; 24:10. [PMID: 36451052 PMCID: PMC9994751 DOI: 10.1208/s12249-022-02460-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/04/2022] [Indexed: 12/02/2022] Open
Abstract
The objective of this study was to develop a new heated dryer system (HDS) for high efficiency lung delivery of nebulized aerosol and demonstrate performance with realistic in vitro testing for trans-nasal aerosol administration simultaneously with high-flow nasal cannula (HFNC) therapy and separately for direct oral inhalation (OI) of the aerosol. With the HDS-HFNC and HDS-OI platforms, new active synchronization control routines were developed to sense subject inhalation and coordinate drug aerosol delivery. In vitro experiments were conducted to predict regional drug loss and lung delivery efficiency in systems that included the HDS with various patient interfaces, realistic airway models, and simulated breathing waveforms. For the HDS-HFNC platform and a repeating breathing waveform, total system loss was < 10%, extrathoracic deposition was approximately 6%, and best-case lung delivery efficiency was 75-78% of nebulized dose. Inclusion of randomized breathing with the HFNC system decreased lung delivery efficiency by ~ 10% and had no impact on nasal depositional loss. For the HDS-OI platform and best-case mouthpiece, total system loss was < 8%, extrathoracic deposition was < 1%, and lung delivery efficiency was > 90% of nebulized dose. Normal vs. deep randomized oral inhalation had little impact on performance of the HDS-OI platform and environmental aerosol loss was negligible. In conclusion, both platforms demonstrated the potential for high efficiency lung delivery of the aerosol with the HDS-OI platform having the added advantages of nearly eliminating extrathoracic deposition, being insensitive to breathing waveform, and preventing environmental aerosol loss.
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Affiliation(s)
- Benjamin M Spence
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA.
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA.
| | - Rabijit Dutta
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mohammad A M Momin
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sarah Strickler
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
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Howe C, Momin MAM, Farkas DR, Bonasera S, Hindle M, Longest PW. Advancement of the Infant Air-Jet Dry Powder Inhaler (DPI): Evaluation of Different Positive-Pressure Air Sources and Flow Rates. Pharm Res 2021; 38:1615-1632. [PMID: 34462876 DOI: 10.1007/s11095-021-03094-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/05/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE In order to improve the delivery of dry powder aerosol formulations to the lungs of infants, this study implemented an infant air-jet platform and explored the effects of different air sources, flow rates, and pulmonary mechanics on aerosolization performance and aerosol delivery through a preterm nose-throat (NT) in vitro model. METHODS The infant air-jet platform was actuated with a positive-pressure air source that delivered the aerosol and provided a full inhalation breath. Three different air sources were developed to provide highly controllable positive-pressure air actuations (using actuation volumes of ~10 mL for the preterm model). While providing different flow waveform shapes, the three air sources were calibrated to produce the same flow rate magnitude (Q90: 90th percentile of flow rate). Multiple air-jet DPI designs were coupled with the air sources and evaluated with a model spray-dried excipient enhanced growth formulation. RESULTS Compared to other designs, the D1-Single air-jet DPI provided improved performance with low variability across all three air sources. With the tested D1-Single air-jet and Timer air source, reducing the flow rate from 4 to 1.7 L/min marginally decreased the aerosol size and significantly increased the lung delivery efficiency above 50% of the loaded dose. These results were not impacted by the presence of downstream pulmonary mechanics (resistance and compliance model). CONCLUSIONS The selected design was capable of providing an estimated >50% lung delivery efficiency of a model spray-dried formulation and was not influenced by the air source, thereby enabling greater flexibility for platform deployment in different environments.
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Affiliation(s)
- Connor Howe
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA
| | - Mohammad A M Momin
- Department of Pharmaceutics, Virginia Commonwealth University, 410 North 12th Street, P.O. Box 980533, Richmond, VA, 23298-0533, USA
| | - Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, 410 North 12th Street, P.O. Box 980533, Richmond, VA, 23298-0533, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, 410 North 12th Street, P.O. Box 980533, Richmond, VA, 23298-0533, USA
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA. .,Department of Pharmaceutics, Virginia Commonwealth University, 410 North 12th Street, P.O. Box 980533, Richmond, VA, 23298-0533, USA.
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Ding L, Brunaugh AD, Stegemann S, Jermain SV, Herpin MJ, Kalafat J, Smyth HDC. A Quality by Design Framework for Capsule-Based Dry Powder Inhalers. Pharmaceutics 2021; 13:1213. [PMID: 34452174 PMCID: PMC8399055 DOI: 10.3390/pharmaceutics13081213] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 12/17/2022] Open
Abstract
Capsule-based dry powder inhalers (cDPIs) are widely utilized in the delivery of pharmaceutical powders to the lungs. In these systems, the fundamental nature of the interactions between the drug/formulation powder, the capsules, the inhaler device, and the patient must be fully elucidated in order to develop robust manufacturing procedures and provide reproducible lung deposition of the drug payload. Though many commercially available DPIs utilize a capsule-based dose metering system, an in-depth analysis of the critical factors associated with the use of the capsule component has not yet been performed. This review is intended to provide information on critical factors to be considered for the application of a quality by design (QbD) approach for cDPI development. The quality target product profile (QTPP) defines the critical quality attributes (CQAs) which need to be understood to define the critical material attributes (CMA) and critical process parameters (CPP) for cDPI development as well as manufacturing and control.
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Affiliation(s)
- Li Ding
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; (L.D.); (A.D.B.); (S.V.J.); (M.J.H.)
| | - Ashlee D. Brunaugh
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; (L.D.); (A.D.B.); (S.V.J.); (M.J.H.)
| | - Sven Stegemann
- Institute for Process and Particle Engineering, Graz University of Technology, 8010 Graz, Austria;
| | - Scott V. Jermain
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; (L.D.); (A.D.B.); (S.V.J.); (M.J.H.)
| | - Matthew J. Herpin
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; (L.D.); (A.D.B.); (S.V.J.); (M.J.H.)
| | - Justin Kalafat
- ACG North America, LLC, 262 Old New Brunswick Road, Suite A, Piscataway, NJ 08854, USA;
| | - Hugh D. C. Smyth
- Division of Molecular Pharmaceutics and Drug Delivery, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, USA; (L.D.); (A.D.B.); (S.V.J.); (M.J.H.)
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Boc S, Momin MAM, Farkas DR, Longest W, Hindle M. Development and Characterization of Excipient Enhanced Growth (EEG) Surfactant Powder Formulations for Treating Neonatal Respiratory Distress Syndrome. AAPS PharmSciTech 2021; 22:136. [PMID: 33860409 DOI: 10.1208/s12249-021-02001-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/22/2021] [Indexed: 12/18/2022] Open
Abstract
This study aimed to develop and characterize a spray-dried powder aerosol formulation of a commercially available surfactant formulation, Survanta® intratracheal suspension, using the excipient enhanced growth (EEG) approach. Survanta EEG powders were prepared by spray drying of the feed dispersions containing Survanta® (beractant) intratracheal suspension, hygroscopic excipients (mannitol and sodium chloride), and a dispersion enhancer (l-leucine or trileucine) in 5 or 20% v/v ethanol in water using the Buchi Nano Spray Dryer B-90 HP. Powders were characterized for primary particle size, morphology, phospholipid content, moisture content, thermal properties, moisture sorption, and surface activity. The aerosol performance of the powders was assessed using a novel low-volume dry powder inhaler (LV-DPI) device operated with 3-mL volume of dispersion air. At both ethanol concentrations, in comparison to trileucine, l-leucine significantly reduced the primary particle size and span and increased the fraction of submicrometer particles of the Survanta EEG powders. The l-leucine-containing Survanta EEG powders exhibited good aerosolization performance with ≥ 88% of the mass emitted (% nominal) after 3 actuations from the modified LV-DPI device. In addition, l-leucine-containing powders had a low moisture content (< 3% w/w) with transition temperatures close to the commercial surfactant formulation and retained their surface tension reducing activity after formulation processing. A Survanta EEG powder containing l-leucine was developed which showed efficient aerosol delivery from the modified LV-DPI device using a low dispersion air volume.
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Boc S, Momin MAM, Farkas DR, Longest W, Hindle M. Performance of Low Air Volume Dry Powder Inhalers (LV-DPI) when Aerosolizing Excipient Enhanced Growth (EEG) Surfactant Powder Formulations. AAPS PharmSciTech 2021; 22:135. [PMID: 33860378 DOI: 10.1208/s12249-021-01998-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/22/2021] [Indexed: 01/10/2023] Open
Abstract
Efficient delivery of dry powder aerosols dispersed with low volumes of air is challenging. This study aims to develop an efficient dry powder inhaler (DPI) capable of delivering spray-dried Survanta-EEG powders (3-10 mg) with a low volume (3 mL) of dispersion air. A series of iterative design modifications were made to a base low air volume actuated DPI. The modifications included the replacement of the original capsule chamber with an integral dose containment chamber, alteration of the entrainment air flow path through the device (from single-sided (SS) to straight through (ST)), change in the number of air inlet holes (from one to three), varying the outlet delivery tube length (45, 55, and 90 mm) and internal diameter (0.60, 0.89, and 1.17 mm). The modified devices were evaluated by determining the influence of the modifications and powder fill mass on aerosol performance of spray-dried Survanta-EEG powders. The optimal DPI was also evaluated for its ability to aerosolize a micronized powder. The optimized dose containment unit DPI had a 0.21 mL powder chamber, ST airflow path, three-0.60 mm air inlet holes, and 90 mm outlet delivery tube with 0.89 mm internal diameter. The powder dispersion characteristics of the optimal device were independent of fill mass with good powder emptying in one 3 mL actuation. At 10 mg fill mass, this device had an emitted mass of 5.3 mg with an aerosol Dv50 of 2.7 μm. After three 3 mL actuations, >85% of the spray-dried powder was emitted from the device. The emitted mass of the optimal device with micronized albuterol sulfate was >72% of the nominal fill mass of 10 mg in one 3 mL actuation. Design optimization produced a DPI capable of efficient performance with a dispersion air volume of 3 mL to aerosolize Survanta-EEG powders.
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Diveky ME, Gleichweit MJ, Roy S, Signorell R. Shining New Light on the Kinetics of Water Uptake by Organic Aerosol Particles. J Phys Chem A 2021; 125:3528-3548. [PMID: 33739837 DOI: 10.1021/acs.jpca.1c00202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The uptake of water vapor by various organic aerosols is important in a number of applications ranging from medical delivery of pharmaceutical aerosols to cloud formation in the atmosphere. The coefficient that describes the probability that the impinging gas-phase molecule sticks to the surface of interest is called the mass accommodation coefficient, αM. Despite the importance of this coefficient for the description of water uptake kinetics, accurate values are still lacking for many systems. In this Feature Article, we present various experimental techniques that have been evoked in the literature to study the interfacial transport of water and discuss the corresponding strengths and limitations. This includes our recently developed technique called photothermal single-particle spectroscopy (PSPS). The PSPS technique allows for a retrieval of αM values from three independent, yet simultaneous measurements operating close to equilibrium, providing a robust assessment of interfacial mass transport. We review the currently available data for αM for water on various organics and discuss the few studies that address the temperature and relative humidity dependence of αM for water on organics. The knowledge of the latter, for example, is crucial to assess the water uptake kinetics of organic aerosols in the Earth's atmosphere. Finally, we argue that PSPS might also be a viable method to better restrict the αM value for water on liquid water.
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Affiliation(s)
- Matus E Diveky
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Michael J Gleichweit
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Sandra Roy
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Ruth Signorell
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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12
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Bass K, Farkas D, Hassan A, Bonasera S, Hindle M, Longest PW. High-Efficiency Dry Powder Aerosol Delivery to Children: Review and Application of New Technologies. JOURNAL OF AEROSOL SCIENCE 2021; 153:105692. [PMID: 33716317 PMCID: PMC7945982 DOI: 10.1016/j.jaerosci.2020.105692] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
While dry powder aerosol formulations offer a number of advantages, their use in children is often limited due to poor lung delivery efficiency and difficulties with consistent dry powder inhaler (DPI) usage. Both of these challenges can be attributed to the typical use of adult devices in pediatric subjects and a lack of pediatric-specific DPI development. In contrast, a number of technologies have recently been developed or progressed that can substantially improve the efficiency and reproducibility of DPI use in children including: (i) nose-to-lung administration with small particles, (ii) active positive-pressure devices, (iii) structures to reduce turbulence and jet momentum, and (iv) highly dispersible excipient enhanced growth particle formulations. In this study, these technologies and their recent development are first reviewed in depth. A case study is then considered in which these technologies are simultaneously applied in order to enable the nose-to-lung administration of dry powder aerosol to children with cystic fibrosis (CF). Using a combination of computational fluid dynamics (CFD) analysis and realistic in vitro experiments, device performance, aerosol size increases and lung delivery efficiency are considered for pediatric-CF subjects in the age ranges of 2-3, 5-6 and 9-10 years old. Results indicate that a new 3D rod array structure significantly improves performance of a nasal cannula reducing interface loss by a factor of 1.5-fold and produces a device emitted mass median aerodynamic diameter (MMAD) of 1.67 μm. For all ages considered, approximately 70% of the loaded dose reaches the lower lung beyond the lobar bronchi. Moreover, significant and rapid size increase of the aerosol is observed beyond the larynx and illustrates the potential for targeting lower airway deposition. In conclusion, concurrent CFD and realistic in vitro analysis indicates that a combination of multiple new technologies can be implemented to overcome obstacles that currently limit the use of DPIs in children as young as two years of age.
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Affiliation(s)
- Karl Bass
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
| | - Dale Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
| | - Amr Hassan
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
- Author Contact Information: Dr. Worth Longest, PhD, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA 23284-3015, Phone: (804)-827-7023, Fax: (804)-827-7030,
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13
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Affiliation(s)
- Andrew R. Martin
- 10-324 Donadeo Innovation Center for Engineering, University of Alberta, Alberta, Canada
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14
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Majoral C, Coates AL, Le Pape A, Vecellio L. Humidified and Heated Cascade Impactor for Aerosol Sizing. Front Bioeng Biotechnol 2020; 8:589782. [PMID: 33282850 PMCID: PMC7691492 DOI: 10.3389/fbioe.2020.589782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/22/2020] [Indexed: 11/21/2022] Open
Abstract
Aerosol sizing is generally measured at ambient air but human airways have different temperature (37°C) and relative humidity (100%) which can affect particle size in airways and consequently deposition prediction. This work aimed to develop and evaluate a new method using cascade impactor to measure particle size at human physiological temperature and humidity (HPTH) taking into account ambient air conditions. A heated and humidified trachea was built and a cascade impactor was heated to 37°C and humidified inside. Four medical aerosols [jet nebulizer, mesh nebulizer, Presurized Metered Dose Inhaler (pMDI), and Dry Powder Inhaler (DPI)] under ambient conditions and at HPTH were tested. MMAD was lower at HPTH for the two nebulizers; it was similar at ambient conditions and HPTH for pMDI, and the mass of particles smaller than 5 μm decreased for DPI at HPTH (51.9 vs. 82.8 μg/puff). In conclusion, we developed a new method to measure particle size at HPTH affecting deposition prediction with relevance. In vivo studies are required to evaluate the interest of this new model to improve the precision of deposition prediction.
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Affiliation(s)
- Caroline Majoral
- INSERM, Research Center for Respiratory Diseases, Tours, France.,Université de Tours, Tours, France
| | | | - Alain Le Pape
- INSERM, Research Center for Respiratory Diseases, Tours, France.,Université de Tours, Tours, France
| | - Laurent Vecellio
- INSERM, Research Center for Respiratory Diseases, Tours, France.,Université de Tours, Tours, France
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15
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CFD Guided Optimization of Nose-to-Lung Aerosol Delivery in Adults: Effects of Inhalation Waveforms and Synchronized Aerosol Delivery. Pharm Res 2020; 37:199. [PMID: 32968848 DOI: 10.1007/s11095-020-02923-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/01/2020] [Indexed: 12/27/2022]
Abstract
PURPOSE The objective of this study was to optimize nose-to-lung aerosol delivery in an adult upper airway model using computational fluid dynamics (CFD) simulations in order to guide subsequent human subject aerosol delivery experiments. METHODS A CFD model was developed that included a new high-flow nasal cannula (HFNC) and pharmaceutical aerosol delivery unit, nasal cannula interface, and adult upper airway geometry. Aerosol deposition predictions in the system were validated with existing and new experimental results. The validated CFD model was then used to explore aerosol delivery parameters related to synchronizing aerosol generation with inhalation and inhalation flow rate. RESULTS The low volume of the new HFNC unit minimized aerosol transit time (0.2 s) and aerosol bolus spread (0.1 s) enabling effective synchronization of aerosol generation with inhalation. For aerosol delivery correctly synchronized with inhalation, a small particle excipient-enhanced growth delivery strategy reduced nasal cannula and nasal depositional losses each by an order of magnitude and enabled ~80% of the nebulized dose to reach the lungs. Surprisingly, nasal deposition was not sensitive to inhalation flow rate due to use of a nasal cannula interface with co-flow inhaled air and the small initial particle size. CONCLUSIONS The combination of correct aerosol synchronization and small particle size enabled high efficiency nose-to-lung aerosol delivery in adults, which was not sensitive to inhalation flow rate.
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16
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Howe C, Hindle M, Bonasera S, Rani V, Longest PW. Initial Development of an Air-Jet Dry Powder Inhaler for Rapid Delivery of Pharmaceutical Aerosols to Infants. J Aerosol Med Pulm Drug Deliv 2020; 34:57-70. [PMID: 32758026 DOI: 10.1089/jamp.2020.1604] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: Positive-pressure dry powder inhalers (DPIs) have recently been developed that in combination with highly dispersible spray-dried powder formulations can achieve high efficiency aerosolization with low actuation air-volumes (AAVs). The objective of this study was to initially develop the positive-pressure air-jet DPI platform for high efficiency aerosol delivery to newborn infants by using the nose-to-lung route. Methods: Aerosolization performance metrics of six air-jet DPIs were first assessed at AAVs that were consistent with full-term (30 mL) and preterm (10 mL) neonates. Designs of the air-jet DPIs varied based on geometry of the inlet and outlet flow passages and shape of the aerosolization chamber. Aerosolization metrics evaluated at the device outlet were emitted dose (ED) and mass median aerodynamic diameter (MMAD). Designs with the best aerosolization performance were connected to a smoothly expanding nasal interface and full-term infant (3550 g) nose-throat (NT) model with tracheal filter. Results: The three best performing devices had characteristics of a cylindrical and horizontal aerosolization chamber with a flush or protruding outlet orifice. Including multiple air inlets resulted in meeting the aerosolization targets of >80% ED (based on loaded dose) and MMAD <1.8 μm. Reducing the AAV by a factor of threefold from 30 to 10 mL had little effect on aerosol formation. The three leading devices all delivered ∼50% of the loaded dose through a full-term NT in vitro model by using an AAV of 30 mL. Conclusion: With careful selection of design attributes, the air-jet DPI platform is capable of high-efficiency aerosolization of a 10 mg powder mass by using AAVs that are consistent with infant inhalation. The associated infant air-jet DPI system, which forms a seal at the nostril(s) and delivers both the aerosol and a complete inhalation, is capable of rapid and efficient aerosol administration to infant lungs, based on initial testing in a full-term in vitro NT model.
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Affiliation(s)
- Connor Howe
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Vijaya Rani
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia, USA
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia, USA.,Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
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17
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Dry powder aerosol containing muco-inert particles for excipient enhanced growth pulmonary drug delivery. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 29:102262. [PMID: 32623017 DOI: 10.1016/j.nano.2020.102262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/21/2020] [Accepted: 06/26/2020] [Indexed: 02/08/2023]
Abstract
Tenacious sputum poses a critical diffusion barrier for aerosol antibiotics used to treat cystic fibrosis (CF) lung infection. We conducted a proof-of-concept study using dense poly(ethylene glycol) coated polystyrene nanoparticles (PS-PEG NPs) as model muco-inert particles (MIPs) formulated as a powder using an excipient enhanced growth (EEG) strategy, aiming to minimize extrathoracic airway loss, maximize deposition in the airway and further overcome the sputum barrier in the CF lungs. The EEG aerosol formulation containing PS-PEG MIPs was prepared by spray drying and produced discrete spherical particles with geometric diameter of approximately 2 μm; and >80% of the powder dose was delivered from a new small-animal dry powder inhaler (DPI). The MIPs released from the EEG aerosol had human airway mucus and CF sputum diffusion properties comparable to the suspension formulation. These properties make this formulation a promising pulmonary drug delivery system for CF lung infections.
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18
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Computational Fluid Dynamics (CFD) Simulations of Spray Drying: Linking Drying Parameters with Experimental Aerosolization Performance. Pharm Res 2020; 37:101. [PMID: 32440940 DOI: 10.1007/s11095-020-02806-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/20/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE The purpose of this study was to develop a new computational fluid dynamics (CFD)-based model of the complex transport and droplet drying kinetics within a laboratory-scale spray dryer, and relate CFD-predicted drying parameters to powder aerosolization metrics from a reference dry powder inhaler (DPI). METHODS A CFD model of the Buchi Nano Spray Dryer B-90 was developed that captured spray dryer conditions from a previous experimental study producing excipient enhanced growth powders with L-leucine as a dispersion enhancer. The CFD model accounted for two-way heat and mass transfer coupling between the phases and turbulent flow created by acoustic streaming from the mesh nebulizer. CFD-based drying parameters were averaged across all droplets in each spray dryer case and included droplet time-averaged drying rate (κavg), maximum instantaneous drying rate (κmax) and precipitation window. RESULTS CFD results highlighted a chaotic drying environment in which time-averaged droplet drying rates (κavg) for each spray dryer case had high variability with coefficients of variation in the range of 60-70%. Maximum instantaneous droplet drying rates (κmax) were discovered that were two orders of magnitude above time-averaged drying rates. Comparing CFD-predicted drying parameters with experimentally determined mass median aerodynamic diameters (MMAD) and emitted doses (ED) from a reference DPI produced strong linear correlations with coefficients of determination as high as R2 = 0.98. CONCLUSIONS For the spray dryer system and conditions considered, reducing the CFD-predicted maximum drying rate experienced by droplets improved the aerosolization performance (both MMAD and ED) when the powders were aerosolized with a reference DPI.
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19
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Kamga Gninzeko FJ, Valentine MS, Tho CK, Chindal SR, Boc S, Dhapare S, Momin MAM, Hassan A, Hindle M, Farkas DR, Longest PW, Heise RL. Excipient Enhanced Growth Aerosol Surfactant Replacement Therapy in an In Vivo Rat Lung Injury Model. J Aerosol Med Pulm Drug Deliv 2020; 33:314-322. [PMID: 32453638 DOI: 10.1089/jamp.2020.1593] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: In neonatal respiratory distress syndrome, breathing support and surfactant therapy are commonly used to enable the alveoli to expand. Surfactants are typically delivered through liquid instillation. However, liquid instillation does not specifically target the small airways. We have developed an excipient enhanced growth (EEG) powder aerosol formulation using Survanta®. Methods: EEG Survanta powder aerosol was delivered using a novel dry powder inhaler via tracheal insufflation to surfactant depleted rats at nominal doses of 3, 5, 10, and 20 mg of powder containing 0.61, 0.97, 1.73, and 3.46 mg of phospholipids (PL), whereas liquid Survanta was delivered via syringe instillation at doses of 2 and 4 mL/kg containing 18.6 and 34 mg of PL. Ventilation mechanics were measured before and after depletion, and after treatment. We hypothesized that EEG Survanta powder aerosol would improve lung mechanics compared with instilled liquid Survanta in surfactant depleted rats. Results and Conclusion: EEG Survanta powder aerosol at a dose of 0.61 mg PL significantly improved lung compliance and elastance compared with the liquid Survanta at a dose of 18.6 mg, which represents improved primary efficacy of the aerosol at a 30-fold lower dose of PL. There was no significant difference in white blood cell count of the lavage from the EEG Survanta group compared with liquid Survanta. These results provide an in vivo proof-of-concept for EEG Survanta powder aerosol as a promising method of surfactant replacement therapy.
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Affiliation(s)
- Franck J Kamga Gninzeko
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael S Valentine
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Cindy K Tho
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sahil R Chindal
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Susan Boc
- Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sneha Dhapare
- Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia, USA
| | | | - Amr Hassan
- Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael Hindle
- Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia, USA
| | - Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Rebecca L Heise
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
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20
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Farkas D, Hindle M, Bonasera S, Bass K, Longest W. Development of an Inline Dry Powder Inhaler for Oral or Trans-Nasal Aerosol Administration to Children. J Aerosol Med Pulm Drug Deliv 2019; 33:83-98. [PMID: 31464559 DOI: 10.1089/jamp.2019.1540] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Background: Dry powder inhalers (DPIs) offer a number of advantages, such as rapid delivery of high-dose inhaled medications; however, DPI use in children is often avoided due to low lung delivery efficiency and difficulty in operating the device. The objective of this study was to develop a high-efficiency inline DPI for administering aerosol therapy to children with the option of using either an oral or trans-nasal approach. Methods: An inline DPI was developed that consisted of hollow inlet and outlet capillaries, a powder chamber, and a nasal or oral interface. A ventilation bag or compressed air was used to actuate the device and simultaneously provide a full deep inspiration consistent with a 5-year-old child. The powder chamber was partially filled with a model spray-dried excipient enhanced growth powder formulation with a mass of 10 mg. Device aerosolization was characterized with cascade impaction, and aerosol transmissions through oral and nasal in vitro models were assessed. Results: Best device performance was achieved when all actuation air passed through the powder chamber (no bypass flow) resulting in an aerosol mean mass median aerodynamic diameter (MMAD) <1.75 μm and a fine particle fraction (<5 μm) ≥90% based on emitted dose. Actuation with the ventilation bag enabled lung delivery efficiency through the nasal and oral interfaces to a tracheal filter of 60% or greater, based on loaded dose. In both oral and nose-to-lung (N2L) administrations, extrathoracic depositional losses were <10%. Conclusion: In conclusion, this study has proposed and initially developed an efficient inline DPI for delivering spray-dried formulations to children using positive pressure operation. Actuation of the device with positive pressure enabled effective N2L aerosol administration with a DPI, which may be beneficial for subjects who are too young to use a mouthpiece or to simultaneously treat the nasal and lung airways of older children.
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Affiliation(s)
- Dale Farkas
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Serena Bonasera
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Karl Bass
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering and Virginia Commonwealth University, Richmond, Virginia.,Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
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21
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Spence BM, Longest W, Wei X, Dhapare S, Hindle M. Development of a High-Flow Nasal Cannula and Pharmaceutical Aerosol Combination Device. J Aerosol Med Pulm Drug Deliv 2019; 32:224-241. [PMID: 30855199 PMCID: PMC6685196 DOI: 10.1089/jamp.2018.1488] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 01/04/2019] [Indexed: 11/12/2022] Open
Abstract
Background: Aerosol drug delivery to the lungs is known to be very inefficient during all forms of noninvasive ventilation, especially when the aerosol is administered simultaneously with high-flow nasal cannula (HFNC) therapy. The objective of this study was to develop a new combination device based on vibrating mesh nebulizers that can provide continuously heated and humidified HFNC therapy as well as on-demand pharmaceutical aerosols with high efficiency. Methods: The combination device implemented separate mesh nebulizers for generating humidity (humidity nebulizer) and delivering the medical aerosol (drug nebulizer). Nebulizers were actuated in an alternating manner with the drug nebulizer delivering the medication during a portion of an adult inhalation cycle. Aerosol entered a small-volume mixing region where it was combined with ventilation gas flow and then entered a heating channel to produce small particles that are desirable for nose-to-lung administration and potentially excipient enhanced growth delivery. Three assessment methods (analytical calculations, computational fluid dynamics [CFD] simulations, and in vitro experiments in three-dimensional [3D] printed devices) were used to improve the mixer-heater design to minimize depositional drug losses, maintain a small device volume, ensure sufficient droplet evaporation, and control the outlet thermodynamic conditions. Results: For an initial configuration (Design 1), good agreement in performance metrics was found using the three assessment methods. Based on insights gained from the CFD simulations of Design 1, two new designs were developed and produced with 3D printing. Experimental analysis indicated that the new designs both achieved <5% depositional loss in the mixer-heater even with cyclic operation and sufficiently dried the aerosol from an initial size of 5.3 μm to an outlet size of ∼1.0 μm. A combination of the applied methods indicated that the desired thermodynamic conditions of HFNC therapy were also met. Conclusions: Multiple methodological approaches were used concurrently to develop a new combination device for administering HFNC therapy and simultaneous on-demand pharmaceutical aerosols to the lungs with high efficiency. The use of a small-volume mixer-heater (<100 mL), synchronization of the drug nebulizer with inhalation, and small outlet particle size should enable high efficiency lung delivery of the aerosol.
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Affiliation(s)
- Benjamin M. Spence
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Xiangyin Wei
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Sneha Dhapare
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
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22
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Moon C, Smyth HDC, Watts AB, Williams RO. Delivery Technologies for Orally Inhaled Products: an Update. AAPS PharmSciTech 2019; 20:117. [PMID: 30783904 DOI: 10.1208/s12249-019-1314-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 01/18/2019] [Indexed: 12/22/2022] Open
Abstract
Orally inhaled products have well-known benefits. They allow for effective local administration of many drugs for the treatment of pulmonary disease, and they allow for rapid absorption and avoidance of first-pass metabolism of several systemically acting drugs. Several challenges remain, however, such as dosing limitations, low and variable deposition of the drug in the lungs, and high drug deposition in the oropharynx region. These challenges have stimulated the development of new delivery technologies. Both formulation improvements and new device technologies have been developed through an improved understanding of the mechanisms of aerosolization and lung deposition. These new advancements in formulations have enabled improved aerosolization by controlling particle properties such as density, size, shape, and surface energy. New device technologies emerging in the marketplace focus on minimizing patient errors, expanding the range of inhaled drugs, improving delivery efficiency, increasing dose consistency and dosage levels, and simplifying device operation. Many of these new technologies have the potential to improve patient compliance. This article reviews how new delivery technologies in the form of new formulations and new devices enhance orally inhaled products.
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23
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Longest PW, Bass K, Dutta R, Rani V, Thomas ML, El-Achwah A, Hindle M. Use of computational fluid dynamics deposition modeling in respiratory drug delivery. Expert Opin Drug Deliv 2019; 16:7-26. [PMID: 30463458 PMCID: PMC6529297 DOI: 10.1080/17425247.2019.1551875] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Respiratory drug delivery is a surprisingly complex process with a number of physical and biological challenges. Computational fluid dynamics (CFD) is a scientific simulation technique that is capable of providing spatially and temporally resolved predictions of many aspects related to respiratory drug delivery from initial aerosol formation through respiratory cellular drug absorption. AREAS COVERED This review article focuses on CFD-based deposition modeling applied to pharmaceutical aerosols. Areas covered include the development of new complete-airway CFD deposition models and the application of these models to develop a next-generation of respiratory drug delivery strategies. EXPERT OPINION Complete-airway deposition modeling is a valuable research tool that can improve our understanding of pharmaceutical aerosol delivery and is already supporting medical hypotheses, such as the expected under-treatment of the small airways in asthma. These complete-airway models are also being used to advance next-generation aerosol delivery strategies, like controlled condensational growth. We envision future applications of CFD deposition modeling to reduce the need for human subject testing in developing new devices and formulations, to help establish bioequivalence for the accelerated approval of generic inhalers, and to provide valuable new insights related to drug dissolution and clearance leading to microdosimetry maps of drug absorption.
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Affiliation(s)
- P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - Karl Bass
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Rabijit Dutta
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Vijaya Rani
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Morgan L. Thomas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Ahmad El-Achwah
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
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Bass K, Boc S, Hindle M, Dodson K, Longest W. High-Efficiency Nose-to-Lung Aerosol Delivery in an Infant: Development of a Validated Computational Fluid Dynamics Method. J Aerosol Med Pulm Drug Deliv 2018; 32:132-148. [PMID: 30556777 DOI: 10.1089/jamp.2018.1490] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: Computational fluid dynamics (CFD) provides a powerful tool for developing new high-efficiency aerosol delivery strategies, such as nose-to-lung (N2L) aerosol administration to infants and children using correctly sized aerosols. The objective of this study was to establish numerically efficient CFD solution methods and guidelines for simulating N2L aerosol administration to an infant based on comparisons with concurrent in vitro experiments. Materials and Methods: N2L administration of a micrometer-sized aerosol (mass median aerodynamic diameter [MMAD] = 1.4 μm) was evaluated using concurrent CFD simulations and in vitro experiments. Aerosol transport and deposition was assessed in a new nasal airway geometry of a 6-month-old infant with a streamlined nasal cannula interface, which was constructed as a CFD mesh and three-dimensionally printed to form an identical physical prototype. CFD meshes explored were a conventional tetrahedral approach with near-wall (NW) prism elements and a new polyhedral mesh style with an equally refined NW layer. The presence of turbulence in the model was evaluated using a highly efficient low-Reynolds number (LRN) k-ω turbulence model, with previously established NW corrections that accounted for anisotropic wall-normal turbulence as well as improved NW velocity interpolations and hydrodynamic particle damping. Results: Use of the new polyhedral mesh was found to improve numerical efficiency by providing more rapid convergence and requiring fewer control volumes. Turbulent flow was found in the nasal geometry, generated by the inlet jets from the nasal cannula interface. However, due to the small particle size, turbulent dispersion was shown to have little effect on deposition. Good agreement was established between the CFD predictions using the numerically efficient LRN k-ω model with appropriate NW corrections and in vitro deposition data. Aerosol transmission efficiencies through the delivery tube, nasal cannula, and infant nasal model, based on experimental and CFD predictions, were 93.0% and 91.5%, respectively. Conclusions: A numerically efficient CFD approach was established to develop transnasal aerosol administration to infants and children. Small particle aerosols with aerodynamic diameters of ∼1.5 μm were confirmed to have low inertial depositional loss, and have low deposition from turbulent dispersion, making them ideal for high-efficiency lung delivery through an infant nasal cannula interface.
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Affiliation(s)
- Karl Bass
- 1 Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Susan Boc
- 2 Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia
| | - Michael Hindle
- 2 Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia
| | - Kelley Dodson
- 3 Department of Otolaryngology-Head and Neck Surgery, Virginia Commonwealth University, Richmond, Virginia
| | - Worth Longest
- 1 Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia.,2 Department of Pharmaceutics, and Virginia Commonwealth University, Richmond, Virginia
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Farkas D, Hindle M, Longest PW. Efficient Nose-to-Lung Aerosol Delivery with an Inline DPI Requiring Low Actuation Air Volume. Pharm Res 2018; 35:194. [PMID: 30132207 DOI: 10.1007/s11095-018-2473-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/03/2018] [Indexed: 11/28/2022]
Abstract
PURPOSE To demonstrate efficient aerosol delivery through an in vitro nasal model using a dry powder inhaler (DPI) requiring low actuation air volumes (LV) applied during low-flow nasal cannula (LFNC) therapy. METHODS A previously developed LV-DPI was connected to a LFNC system with 4 mm diameter tubing. System connections and the nasal cannula interface were replaced with streamlined components. To simulate nasal respiration, an in vitro nasal model was connected to a downstream lung simulator that produced either passive or deep nasal respiration. Performance of a commercial mesh nebulizer system was also considered. RESULTS For the optimized system, steady state cannula emitted dose was 75% of the capsule loaded dose. With cyclic nasal breathing, delivery efficiency to the tracheal filter was 53-55% of the loaded dose, which was just under the design target of 60%. Compared with a commercially available mesh nebulizer, the optimal LV-DPI was 40-fold more efficient and 150 times faster in terms of delivering aerosol to the lungs. CONCLUSIONS The optimized LV-DPI system is capable of high efficiency lung delivery of powder aerosols through a challenging nasal cannula interface.
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Affiliation(s)
- Dale Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015 Richmond, Virginia, 23284-3015, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University Richmond, Virginia, USA
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015 Richmond, Virginia, 23284-3015, USA. .,Department of Pharmaceutics, Virginia Commonwealth University Richmond, Virginia, USA.
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Brunaugh AD, Smyth HDC. Formulation techniques for high dose dry powders. Int J Pharm 2018; 547:489-498. [PMID: 29778822 DOI: 10.1016/j.ijpharm.2018.05.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 01/08/2023]
Abstract
Delivery of drugs to the lungs via dry powder inhaler (DPI) is a promising approach for the treatment of both local pulmonary conditions and systemic diseases. Though DPIs are widely used for the pulmonary deposition of potent bronchodilators, anticholinergics, and corticosteroids, there is growing interest in the utilization of this delivery system for the administration of high drug doses to the lungs, as made evident by recent regulatory approvals for anti-microbial, anti-viral and osmotic agents. However, the formulation of high dose DPIs carries several challenges from both a physiological and physicochemical standpoint. This review describes the various formulation techniques utilized to overcome the barriers associated with the pulmonary delivery of high dose powders.
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Affiliation(s)
- Ashlee D Brunaugh
- University of Texas at Austin, College of Pharmacy, Division of Molecular Pharmaceutics and Drug Delivery, 2409 West University Avenue, Austin, TX 78712, United States
| | - Hugh D C Smyth
- University of Texas at Austin, College of Pharmacy, Division of Molecular Pharmaceutics and Drug Delivery, 2409 West University Avenue, Austin, TX 78712, United States; LaMontagne Center for Infectious Disease, The University of Texas at Austin, United States.
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Farkas D, Hindle M, Longest PW. Development of an Inline Dry Powder Inhaler That Requires Low Air Volume. J Aerosol Med Pulm Drug Deliv 2017; 31:255-265. [PMID: 29261454 DOI: 10.1089/jamp.2017.1424] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Inline dry powder inhalers (DPIs) are actuated by an external air source and have distinct advantages for delivering aerosols to infants and children, and to individuals with compromised lung function or who require ventilator support. However, current inline DPIs either perform poorly, are difficult to operate, and/or require large volumes (∼1 L) of air. The objective of this study was to develop and characterize a new inline DPI for aerosolizing spray-dried formulations with powder masses of 10 mg and higher using a dispersion air volume of 10 mL per actuation that is easy to load (capsule-based) and operate. METHODS Primary features of the new low air volume (LV) DPIs are fixed hollow capillaries that both pierce the capsule and provide a continuous flow path for air and aerosol passing through the device. Two different configurations were evaluated, which were a straight-through (ST) device, with the inlet and outlet capillaries on opposite ends of the capsule, and a single-sided (SS) device, with both the inlet and outlet capillaries on the same side of the capsule. The devices were operated with five actuations of a 10 mL air syringe using an albuterol sulfate (AS) excipient-enhanced growth (EEG) formulation. Device emptying and aerosol characteristics were evaluated for multiple device outlet configurations. RESULTS Each device had specific advantages. The best case ST device produced the smallest aerosol [mean mass median aerodynamic diameter (MMAD) = 1.57 μm; fine particle fraction <5 μm (FPF<5μm) = 95.2%)] but the mean emitted dose (ED) was 61.9%. The best case SS device improved ED (84.8%), but produced a larger aerosol (MMAD = 2.13 μm; FPF<5μm = 89.3%) that was marginally higher than the initial deaggregation target. CONCLUSIONS The new LV-DPIs produced an acceptable high-quality aerosol with only 10 mL of dispersion air per actuation and were easy to load and operate. This performance should enable application in high and low flow mechanical ventilation systems and high efficiency lung delivery to both infants and children.
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Affiliation(s)
- Dale Farkas
- 1 Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia
| | - Michael Hindle
- 2 Department of Pharmaceutics, Virginia Commonwealth University , Richmond, Virginia
| | - P Worth Longest
- 1 Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia.,2 Department of Pharmaceutics, Virginia Commonwealth University , Richmond, Virginia
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Carvalho TC, McConville JT. The function and performance of aqueous aerosol devices for inhalation therapy. ACTA ACUST UNITED AC 2016; 68:556-78. [PMID: 27061412 DOI: 10.1111/jphp.12541] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 02/05/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVES In this review paper, we explore the interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations for several types of devices, namely jet, ultrasonic and vibrating-mesh nebulizers; colliding and extruded jets; electrohydrodynamic mechanism; surface acoustic wave microfluidic atomization; and capillary aerosol generation. KEY FINDINGS Nebulization is the transformation of bulk liquids into droplets. For inhalation therapy, nebulizers are widely used to aerosolize aqueous systems, such as solutions and suspensions. The interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations plays a significant role in the performance of aerosol generation appropriate for pulmonary delivery. Certain types of nebulizers have consistently presented temperature increase during the nebulization event. Therefore, careful consideration should be given when evaluating thermo-labile drugs, such as protein therapeutics. We also present the general approaches for characterization of nebulizer formulations. SUMMARY In conclusion, the interplay between the dosage form (i.e. aqueous systems) and the specific type of device for aerosol generation determines the effectiveness of drug delivery in nebulization therapies, thus requiring extensive understanding and characterization.
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Affiliation(s)
- Thiago C Carvalho
- Bristol-Myers Squibb, Drug Product Science & Technology, New Brunswick, NJ, USA
| | - Jason T McConville
- Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, NM, USA
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Darquenne C, Fleming JS, Katz I, Martin AR, Schroeter J, Usmani OS, Venegas J, Schmid O. Bridging the Gap Between Science and Clinical Efficacy: Physiology, Imaging, and Modeling of Aerosols in the Lung. J Aerosol Med Pulm Drug Deliv 2016; 29:107-26. [PMID: 26829187 DOI: 10.1089/jamp.2015.1270] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Development of a new drug for the treatment of lung disease is a complex and time consuming process involving numerous disciplines of basic and applied sciences. During the 2015 Congress of the International Society for Aerosols in Medicine, a group of experts including aerosol scientists, physiologists, modelers, imagers, and clinicians participated in a workshop aiming at bridging the gap between basic research and clinical efficacy of inhaled drugs. This publication summarizes the current consensus on the topic. It begins with a short description of basic concepts of aerosol transport and a discussion on targeting strategies of inhaled aerosols to the lungs. It is followed by a description of both computational and biological lung models, and the use of imaging techniques to determine aerosol deposition distribution (ADD) in the lung. Finally, the importance of ADD to clinical efficacy is discussed. Several gaps were identified between basic science and clinical efficacy. One gap between scientific research aimed at predicting, controlling, and measuring ADD and the clinical use of inhaled aerosols is the considerable challenge of obtaining, in a single study, accurate information describing the optimal lung regions to be targeted, the effectiveness of targeting determined from ADD, and some measure of the drug's effectiveness. Other identified gaps were the language and methodology barriers that exist among disciplines, along with the significant regulatory hurdles that need to be overcome for novel drugs and/or therapies to reach the marketplace and benefit the patient. Despite these gaps, much progress has been made in recent years to improve clinical efficacy of inhaled drugs. Also, the recent efforts by many funding agencies and industry to support multidisciplinary networks including basic science researchers, R&D scientists, and clinicians will go a long way to further reduce the gap between science and clinical efficacy.
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Affiliation(s)
- Chantal Darquenne
- 1 Department of Medicine, University of California , San Diego, La Jolla, California
| | - John S Fleming
- 2 National Institute of Health Research Biomedical Research Unit in Respiratory Disease , Southampton, United Kingdom .,3 Department of Medical Physics and Bioengineering, University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom
| | - Ira Katz
- 4 Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay , Jouy-en-Josas, France .,5 Department of Mechanical Engineering, Lafayette College , Easton, Pennsylvania
| | - Andrew R Martin
- 6 Department of Mechanical Engineering, University of Alberta , Edmonton, Alberta, Canada
| | | | - Omar S Usmani
- 8 Airway Disease Section, National Heart and Lung Institute , Imperial College London and Royal Brompton Hospital, London, United Kingdom
| | - Jose Venegas
- 9 Department of Anesthesia (Bioengineering), MGH/Harvard, Boston, Massachusetts
| | - Otmar Schmid
- 10 Comprehensive Pneumology Center (CPC), Member of the German Center for Lung Research , Munich, Germany .,11 Institute of Lung Biology and Disease, Helmholtz Zentrum München-German Research Center for Environmental Health , Neuherberg, Germany
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Fitzgerald C, Hosny NA, Tong H, Seville PC, Gallimore PJ, Davidson NM, Athanasiadis A, Botchway SW, Ward AD, Kalberer M, Kuimova MK, Pope FD. Fluorescence lifetime imaging of optically levitated aerosol: a technique to quantitatively map the viscosity of suspended aerosol particles. Phys Chem Chem Phys 2016; 18:21710-9. [DOI: 10.1039/c6cp03674k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A technique to measure the viscosity of stably levitated single micron-sized aerosol particles.
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Affiliation(s)
- C. Fitzgerald
- Department of Chemistry
- University of Cambridge
- Cambridge
- UK
| | - N. A. Hosny
- Department of Chemistry
- Imperial College London
- London
- UK
| | - H. Tong
- Department of Chemistry
- University of Cambridge
- Cambridge
- UK
| | - P. C. Seville
- School of Pharmacy and Biomedical Sciences
- University of Central Lancashire
- Preston
- UK
| | | | - N. M. Davidson
- School of Geography
- Earth and Environmental Sciences
- University of Birmingham
- Birmingham
- UK
| | | | - S. W. Botchway
- The Science and Technology Facilities Council
- Rutherford Appleton Laboratory
- Research Complex at Harwell
- Oxfordshire
- UK
| | - A. D. Ward
- The Science and Technology Facilities Council
- Rutherford Appleton Laboratory
- Research Complex at Harwell
- Oxfordshire
- UK
| | - M. Kalberer
- Department of Chemistry
- University of Cambridge
- Cambridge
- UK
| | - M. K. Kuimova
- Department of Chemistry
- Imperial College London
- London
- UK
| | - F. D. Pope
- School of Geography
- Earth and Environmental Sciences
- University of Birmingham
- Birmingham
- UK
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Farkas DR, Hindle M, Longest PW. Characterization of a New High-Dose Dry Powder Inhaler (DPI) Based on a Fluidized Bed Design. Ann Biomed Eng 2015; 43:2804-15. [PMID: 25986955 DOI: 10.1007/s10439-015-1335-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/08/2015] [Indexed: 01/13/2023]
Abstract
The objective of this study was to develop a new high-efficiency dry powder inhaler (DPI) that can effectively aerosolize large masses (25-100 mg) of spray dried powder formulations. The DPI was designed to implement a concept similar to a fluidized bed for aerosolization using small mixing balls made of polytetrafluoroethylene along with a larger, hollow dosing sphere filled with the powder. The performance of the fluidized bed DPI was compared, based on emitted dose (ED) and aerosolization efficiency, to other recently developed capsule-based DPIs that were designed to accommodate smaller powder masses (~2-20 mg). The inhalers were tested with spray dried excipient enhanced growth (EEG) formulations that contained an antibiotic (ciprofloxacin) and hygroscopic excipient (mannitol). The new fluidized bed design produced an ED of 71% along with a mass median aerodynamic diameter of 1.53 μm and fine particle fractions <5 and 1 μm of 93 and 36%, respectively, when used to deliver a 100 mg loaded mass of EEG powder with the advantage of not requiring multiple capsules. Surprisingly, performance of the device was further improved by removing the mixing balls from the inhaler and only retaining the dose containment sphere.
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Affiliation(s)
- Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA.
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA.
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Kleinstreuer C, Feng Y, Childress E. Drug-targeting methodologies with applications: A review. World J Clin Cases 2014; 2:742-756. [PMID: 25516850 PMCID: PMC4266823 DOI: 10.12998/wjcc.v2.i12.742] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/23/2014] [Accepted: 10/16/2014] [Indexed: 02/05/2023] Open
Abstract
Targeted drug delivery to solid tumors is a very active research area, focusing mainly on improved drug formulation and associated best delivery methods/devices. Drug-targeting has the potential to greatly improve drug-delivery efficacy, reduce side effects, and lower the treatment costs. However, the vast majority of drug-targeting studies assume that the drug-particles are already at the target site or at least in its direct vicinity. In this review, drug-delivery methodologies, drug types and drug-delivery devices are discussed with examples in two major application areas: (1) inhaled drug-aerosol delivery into human lung-airways; and (2) intravascular drug-delivery for solid tumor targeting. The major problem addressed is how to deliver efficiently the drug-particles from the entry/infusion point to the target site. So far, most experimental results are based on animal studies. Concerning pulmonary drug delivery, the focus is on the pros and cons of three inhaler types, i.e., pressurized metered dose inhaler, dry powder inhaler and nebulizer, in addition to drug-aerosol formulations. Computational fluid-particle dynamics techniques and the underlying methodology for a smart inhaler system are discussed as well. Concerning intravascular drug-delivery for solid tumor targeting, passive and active targeting are reviewed as well as direct drug-targeting, using optimal delivery of radioactive microspheres to liver tumors as an example. The review concludes with suggestions for future work, considereing both pulmonary drug targeting and direct drug delivery to solid tumors in the vascular system.
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Walenga RL, Tian G, Hindle M, Yelverton J, Dodson K, Longest PW. Variability in Nose-to-Lung Aerosol Delivery. JOURNAL OF AEROSOL SCIENCE 2014; 78:11-29. [PMID: 25308992 PMCID: PMC4187112 DOI: 10.1016/j.jaerosci.2014.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nasal delivery of lung targeted pharmaceutical aerosols is ideal for drugs that need to be administered during high flow nasal cannula (HFNC) gas delivery, but based on previous studies losses and variability through both the delivery system and nasal cavity are expected to be high. The objective of this study was to assess the variability in aerosol delivery through the nose to the lungs with a nasal cannula interface for conventional and excipient enhanced growth (EEG) delivery techniques. A database of nasal cavity computed tomography (CT) scans was collected and analyzed, from which four models were selected to represent a wide range of adult anatomies, quantified based on the nasal surface area-to-volume ratio (SA/V). Computational fluid dynamics (CFD) methods were validated with existing in vitro data and used to predict aerosol delivery through a streamlined nasal cannula and the four nasal models at a steady state flow rate of 30 L/min. Aerosols considered were solid particles for EEG delivery (initial 0.9 μm and 1.5 μm aerodynamic diameters) and conventional droplets (5 μm) for a control case. Use of the EEG approach was found to reduce depositional losses in the nasal cavity by an order of magnitude and substantially reduce variability. Specifically, for aerosol deposition efficiency in the four geometries, the 95% confidence intervals (CI) for 0.9 and 5 μm aerosols were 2.3-3.1 and 15.5-66.3%, respectively. Simulations showed that the use of EEG as opposed to conventional methods improved delivered dose of aerosols through the nasopharynx, expressed as penetration fraction (PF), by approximately a factor of four. Variability of PF, expressed by the coefficient of variation (CV), was reduced by a factor of four with EEG delivery compared with the control case. Penetration fraction correlated well with SA/V for larger aerosols, but smaller aerosols showed some dependence on nasopharyngeal exit hydraulic diameter. In conclusion, results indicated that the EEG technique not only improved lung aerosol delivery, but largely eliminated variability in both nasal depositional loss and lung PF in a newly developed set of nasal airway models.
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Affiliation(s)
- Ross L Walenga
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
| | - Geng Tian
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - Joshua Yelverton
- Department of Otolaryngology – Head and Neck Surgery, Virginia Commonwealth University, Richmond, VA
| | - Kelley Dodson
- Department of Otolaryngology – Head and Neck Surgery, Virginia Commonwealth University, Richmond, VA
| | - P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
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Muralidharan P, Hayes D, Mansour HM. Dry powder inhalers in COPD, lung inflammation and pulmonary infections. Expert Opin Drug Deliv 2014; 12:947-62. [PMID: 25388926 DOI: 10.1517/17425247.2015.977783] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The number of pulmonary diseases that are effectively treated by aerosolized medicine continues to grow. AREAS COVERED These diseases include chronic obstructive pulmonary disease (COPD), lung inflammatory diseases (e.g., asthma) and pulmonary infections. Dry powder inhalers (DPIs) exhibit many unique advantages that have contributed to the incredible growth in the number of DPI pharmaceutical products. To improve the performance, there are a relatively large number of DPI devices available for different inhalable powder formulations. The relationship between formulation and inhaler device features on performance of the drug-device combination product is critical. Aerosol medicine products are drug-device combination products. Device design and compatibility with the formulation are key drug-device combination product aspects in delivering drugs to the lungs as inhaled powders. In addition to discussing pulmonary diseases, this review discusses DPI devices, respirable powder formulation and their interactions in the context of currently marketed DPI products used in the treatment of COPD, asthma and pulmonary infections. EXPERT OPINION There is a growing line of product options available for patients in choosing inhalers for treatment of respiratory diseases. Looking ahead, combining nanotechnology with optimized DPI formulation and enhancing device design presents a promising future for DPI development.
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Affiliation(s)
- Priya Muralidharan
- The University of Arizona, College of Pharmacy, Skaggs Pharmaceutical Sciences Center , 1703 E. Mabel St, Tucson, AZ 85721 , USA +1 520 626 2768 ; +1 520 6262 7355 ;
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Longest PW, Azimi M, Hindle M. Optimal delivery of aerosols to infants during mechanical ventilation. J Aerosol Med Pulm Drug Deliv 2014; 27:371-85. [PMID: 24299500 PMCID: PMC4227441 DOI: 10.1089/jamp.2013.1077] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 10/17/2013] [Indexed: 02/06/2023] Open
Abstract
PURPOSE The objective of this study was to determine optimal aerosol delivery conditions for a full-term (3.6 kg) infant receiving invasive mechanical ventilation by evaluating the effects of aerosol particle size, a new wye connector, and timing of aerosol delivery. METHODS In vitro experiments used a vibrating mesh nebulizer and evaluated drug deposition fraction and emitted dose through ventilation circuits containing either a commercial (CM) or new streamlined (SL) wye connector and 3-mm endotracheal tube (ETT) for aerosols with mass median aerodynamic diameters of 880 nm, 1.78 μm, and 4.9 μm. The aerosol was released into the circuit either over the full inhalation cycle (T1 delivery) or over the first half of inhalation (T2 delivery). Validated computational fluid dynamics (CFD) simulations and whole-lung model predictions were used to assess lung deposition and exhaled dose during cyclic ventilation. RESULTS In vitro experiments at a steady-state tracheal flow rate of 5 L/min resulted in 80-90% transmission of the 880-nm and 1.78-μm aerosols from the ETT. Based on CFD simulations with cyclic ventilation, the SL wye design reduced depositional losses in the wye by a factor of approximately 2-4 and improved lung delivery efficiencies by a factor of approximately 2 compared with the CM device. Delivery of the aerosol over the first half of the inspiratory cycle (T2) reduced exhaled dose from the ventilation circuit by a factor of 4 compared with T1 delivery. Optimal lung deposition was achieved with the SL wye connector and T2 delivery, resulting in 45% and 60% lung deposition for optimal polydisperse (∼1.78 μm) and monodisperse (∼2.5 μm) particle sizes, respectively. CONCLUSIONS Optimization of selected factors and use of a new SL wye connector can substantially increase the lung delivery efficiency of medical aerosols to infants from current values of <1-10% to a range of 45-60%.
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Affiliation(s)
- P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - Mandana Azimi
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA
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36
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Longest PW, Golshahi L, Behara SRB, Tian G, Farkas DR, Hindle M. Efficient Nose-to-Lung (N2L) Aerosol Delivery with a Dry Powder Inhaler. J Aerosol Med Pulm Drug Deliv 2014; 28:189-201. [PMID: 25192072 DOI: 10.1089/jamp.2014.1158] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PURPOSE Delivering aerosols to the lungs through the nasal route has a number of advantages, but its use has been limited by high depositional loss in the extrathoracic airways. The objective of this study was to evaluate the nose-to-lung (N2L) delivery of excipient enhanced growth (EEG) formulation aerosols generated with a new inline dry powder inhaler (DPI). The device was also adapted to enable aerosol delivery to a patient simultaneously receiving respiratory support from high flow nasal cannula (HFNC) therapy. METHODS The inhaler delivered the antibiotic ciprofloxacin, which was formulated as submicrometer combination particles containing a hygroscopic excipient prepared by spray-drying. Nose-to-lung delivery was assessed using in vitro and computational fluid dynamics (CFD) methods in an airway model that continued through the upper tracheobronchial region. RESULTS The best performing device contained a 2.3 mm flow control orifice and a 3D rod array with a 3-4-3 rod pattern. Based on in vitro experiments, the emitted dose from the streamlined nasal cannula had a fine particle fraction <5 μm of 95.9% and mass median aerodynamic diameter of 1.4 μm, which was considered ideal for nose-to-lung EEG delivery. With the 2.3-343 device, condensational growth in the airways increased the aerosol size to 2.5-2.7 μm and extrathoracic deposition was <10%. CFD results closely matched the in vitro experiments and predicted that nasal deposition was <2%. CONCLUSIONS The developed DPI produced high efficiency aerosolization with significant size increase of the aerosol within the airways that can be used to enable nose-to-lung delivery and aerosol administration during HFNC therapy.
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Affiliation(s)
- P Worth Longest
- 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia.,2Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Laleh Golshahi
- 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Srinivas R B Behara
- 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia.,2Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
| | - Geng Tian
- 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Dale R Farkas
- 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia
| | - Michael Hindle
- 2Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
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Development of a new technique for the efficient delivery of aerosolized medications to infants on mechanical ventilation. Pharm Res 2014; 32:321-36. [PMID: 25103332 DOI: 10.1007/s11095-014-1466-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 07/24/2014] [Indexed: 01/19/2023]
Abstract
PURPOSE To evaluate the efficiency of a new technique for delivering aerosols to intubated infants that employs a new Y-connector, access port administration of a dry powder, and excipient enhanced growth (EEG) formulation particles that change size in the airways. METHODS A previously developed CFD model combined with algebraic correlations were used to predict delivery system and lung deposition of typical nebulized droplets (MMAD = 4.9 μm) and EEG dry powder aerosols. The delivery system consisted of a Y-connector [commercial (CM); streamlined (SL); or streamlined with access port (SL-port)] attached to a 4-mm diameter endotracheal tube leading to the airways of a 6-month-old infant. RESULTS Compared to the CM device and nebulized aerosol, the EEG approach with an initial 0.9 μm aerosol combined with the SL and SL-port geometries reduced device depositional losses by factors of 3-fold and >10-fold, respectively. With EEG powder aerosols, the SL geometry provided the maximum tracheobronchial deposition fraction (55.7%), whereas the SL-port geometry provided the maximum alveolar (67.6%) and total lung (95.7%) deposition fractions, respectively. CONCLUSIONS Provided the aerosol can be administered in the first portion of the inspiration cycle, the proposed new method can significantly improve the deposition of pharmaceutical aerosols in the lungs of intubated infants.
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Behara SRB, Longest PW, Farkas DR, Hindle M. Development of high efficiency ventilation bag actuated dry powder inhalers. Int J Pharm 2014; 465:52-62. [PMID: 24508552 PMCID: PMC4051231 DOI: 10.1016/j.ijpharm.2014.01.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 01/30/2014] [Indexed: 01/19/2023]
Abstract
New active dry powder inhaler systems were developed and tested to efficiently aerosolize a carrier-free formulation. To assess inhaler performance, a challenging case study of aerosol lung delivery during high-flow nasal cannula (HFNC) therapy was selected. The active delivery system consisted of a ventilation bag for actuating the device, the DPI containing a flow control orifice and 3D rod array, and streamlined nasal cannula with separate inlets for the aerosol and HFNC therapy gas. In vitro experiments were conducted to assess deposition in the device, emitted dose (ED) from the nasal cannula, and powder deaggregation. The best performing systems achieved EDs of 70-80% with fine particle fractions <5 μm of 65-85% and mass median aerodynamic diameters of 1.5 μm, which were target conditions for controlled condensational growth aerosol delivery. Decreasing the size of the flow control orifice from 3.6 to 2.3mm reduced the flow rate through the system with manual bag actuations from an average of 35 to 15LPM, while improving ED and aerosolization performance. The new devices can be applied to improve aerosol delivery during mechanical ventilation, nose-to-lung aerosol administration, and to assist patients that cannot reproducibly use passive DPIs.
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Affiliation(s)
- Srinivas R B Behara
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States; Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
| | - P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States; Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States.
| | - Dale R Farkas
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, United States
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, United States
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Tian G, Hindle M, Longest PW. Targeted Lung Delivery of Nasally Administered Aerosols. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2014; 48:434-449. [PMID: 24932058 PMCID: PMC4051279 DOI: 10.1080/02786826.2014.887829] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Using the nasal route to deliver pharmaceutical aerosols to the lungs has a number of advantages including co-administration during non-invasive ventilation. The objective of this study was to evaluate the growth and deposition characteristics of nasally administered aerosol throughout the conducting airways based on delivery with streamlined interfaces implementing two forms of controlled condensational growth technology. Characteristic conducting airways were considered including a nose-mouth-throat (NMT) geometry, complete upper tracheobronchial (TB) model through the third bifurcation (B3), and stochastic individual path (SIP) model to the terminal bronchioles (B15). Previously developed streamlined nasal cannula interfaces were used for the delivery of submicrometer particles using either enhanced condensational growth (ECG) or excipient enhanced growth (EEG) techniques. Computational fluid dynamics (CFD) simulations predicted aerosol transport, growth and deposition for a control (4.7 μm) and three submicrometer condensational aerosols with budesonide as a model insoluble drug. Depositional losses with condensational aerosols in the cannula and NMT were less than 5% of the initial dose, which represents an order-of-magnitude reduction compared to the control. The condensational growth techniques increased the TB dose by a factor of 1.1-2.6x, delivered at least 70% of the dose to the alveolar region, and produced final aerosol sizes ≥2.5 μm. Compared to multiple commercial orally inhaled products, the nose-to-lung delivery approach increased dose to the biologically important lower TB region by factors as large as 35x. In conclusion, nose-to-lung delivery with streamlined nasal cannulas and condensational aerosols was highly efficient and targeted deposition to the lower TB and alveolar regions.
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Affiliation(s)
- Geng Tian
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia, USA
- Address correspondence to: P. Worth Longest, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA 23284-3015, USA.
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Behara SRB, Longest PW, Farkas DR, Hindle M. Development and comparison of new high-efficiency dry powder inhalers for carrier-free formulations. J Pharm Sci 2013; 103:465-77. [PMID: 24307605 DOI: 10.1002/jps.23775] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/27/2013] [Accepted: 10/17/2013] [Indexed: 11/09/2022]
Abstract
High-efficiency dry powder inhalers (DPIs) were developed and tested for use with carrier-free formulations across a range of different inhalation flow rates. Performance of a previously reported DPI was compared with two new designs in terms of emitted dose (ED) and aerosolization characteristics using in vitro experiments. The two new designs oriented the capsule chamber (CC) at different angles to the main flow passage, which contained a three-dimensional (3D) rod array for aerosol deaggregation. Computational fluid dynamics simulations of a previously developed deaggregation parameter, the nondimensional specific dissipation (NDSD), were used to explain device performance. Orienting the CC at 90° to the mouthpiece, the CC90 -3D inhaler provided the best performance with an ED = 73.4%, fine particle fractions (FPFs) less than 5 and 1 μm of 95.1% and 31.4%, respectively, and a mass median aerodynamic diameter (MMAD) = 1.5 μm. For the carrier-free formulation, deaggregation was primarily influenced by capsule aperture position and the NDSD parameter. The new CC-3D inhalers reduced the percent difference in FPF and MMAD between low and high flows by 1-2 orders of magnitude compared with current commercial devices. In conclusion, the new CC-3D inhalers produced extremely high-quality aerosols with little sensitivity to flow rate and are expected to deliver approximately 95% of the ED to the lungs.
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Affiliation(s)
- Srinivas R B Behara
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia; Department of Pharmaceutics, Virginia Commonwealth University, Richmond, Virginia
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Tian G, Longest PW, Li X, Hindle M. Targeting aerosol deposition to and within the lung airways using excipient enhanced growth. J Aerosol Med Pulm Drug Deliv 2013; 26:248-65. [PMID: 23286828 PMCID: PMC3826577 DOI: 10.1089/jamp.2012.0997] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 10/10/2012] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Previous studies have characterized the size increase of combination submicrometer particles composed of a drug and hygroscopic excipient when exposed to typical airway thermodynamic conditions. The objective of this study was to determine the deposition and size increase characteristics of excipient enhanced growth (EEG) aerosols throughout the tracheobronchial (TB) airways and to evaluate the potential for targeted delivery. METHODS Submicrometer particles composed of a poorly water-soluble drug (insulin) and hygroscopic excipient (sodium chloride) were considered at drug:excipient mass ratios of 50:50 and 25:75. A previously validated computational fluid dynamics model was used to predict aerosol size increase and deposition in characteristic geometries of the mouth-throat (MT), upper TB airways through the third bifurcation (B3), and remaining TB airways through B15. Additional validation experiments were also performed for albuterol sulfate:mannitol particles. Both growth of combination particles and deposition are reported throughout the conducting airways for characteristic slow and deep (SD) and quick and deep (QD) inhalations. RESULTS For all EEG cases considered, MT deposition was less than 1% of the drug dose, which is at least one order of magnitude lower than with state-of-the-art and conventional inhalers. Final aerosol sizes exiting the TB region and entering the alveolar airways were all greater than 3 μm. For SD inhalation, deposition fractions of 20% were achieved in the lower TB region of B8-B15, which is a factor of 20-30×higher than conventional delivery devices. With QD inhalation, maximum alveolar delivery of 90% was observed. CONCLUSIONS Increasing the dose delivered to the lower TB region by a factor of 20-30×or achieving 90% delivery to the alveolar airways was considered effective aerosol targeting compared with conventional devices. The trend of higher flow rates resulting in better alveolar delivery of aerosols is unique to EEG and may be used to design highly efficient dry powder inhalers.
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Affiliation(s)
- Geng Tian
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284
| | - P. Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA 23284
| | - Xiang Li
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA 23284
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA 23284
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Behara SRB, Farkas DR, Hindle M, Longest PW. Development of a high efficiency dry powder inhaler: effects of capsule chamber design and inhaler surface modifications. Pharm Res 2013; 31:360-72. [PMID: 23949304 DOI: 10.1007/s11095-013-1165-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/28/2013] [Indexed: 01/31/2023]
Abstract
PURPOSE The objective of this study was to explore the performance of a high efficiency dry powder inhaler (DPI) intended for excipient enhanced growth (EEG) aerosol delivery based on changes to the capsule orientation and surface modifications of the capsule and device. METHODS DPIs were constructed by combining newly designed capsule chambers (CC) with a previously developed three-dimensional (3D) rod array for particle deagglomeration and a previously optimized EEG formulation. The new CCs oriented the capsule perpendicular to the incoming airflow and were analyzed for different air inlets at a constant pressure drop across the device. Modifications to the inhaler and capsule surfaces included use of metal dispersion rods and surface coatings. Aerosolization performance of the new DPIs was evaluated and compared with commercial devices. RESULTS The proposed capsule orientation and motion pattern increased capsule vibrational frequency and reduced the aerosol MMAD compared with commercial/modified DPIs. The use of metal rods in the 3D array further improved inhaler performance. Coating the inhaler and capsule with PTFE significantly increased emitted dose (ED) from the optimized DPI. CONCLUSIONS High efficiency performance is achieved for EEG delivery with the optimized DPI device and formulation combination producing an aerosol with MMAD < 1.5 μm, FPF<5 μm/ED > 90%, and ED > 80%.
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Affiliation(s)
- Srinivas R B Behara
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, Virginia, 23284-3015, USA
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The use of condensational growth methods for efficient drug delivery to the lungs during noninvasive ventilation high flow therapy. Pharm Res 2013; 30:2917-30. [PMID: 23801087 DOI: 10.1007/s11095-013-1123-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE The objective of this study was to evaluate the delivery of nasally administered aerosols to the lungs during noninvasive ventilation using controlled condensational growth techniques. METHODS An optimized mixer, combined with a mesh nebulizer, was used to generate submicrometer aerosol particles using drug alone (albuterol sulfate) and with mannitol or sodium chloride added as hygroscopic excipients. The deposition and growth of these particles were evaluated in an adult nose-mouth-throat (NMT) model using in vitro experimental methods and computational fluid dynamics simulations. RESULTS Significant improvement in the lung dose (3-4× increase) was observed using excipient enhanced growth (EEG) and enhanced condensational growth (ECG) delivery modes compared to control studies performed with a conventional size aerosol (~5 μm). This was due to reduced device retention and minimal deposition in the NMT airways. Increased condensational growth of the initially submicrometer particles was observed using the ECG mode and in the presence of hygroscopic excipients. CFD predictions for regional drug deposition and aerosol size increase were in good agreement with the observed experimental results. CONCLUSIONS These controlled condensational growth techniques for the delivery of submicrometer aerosols were found to be highly efficient methods for delivering nasally-administered drugs to the lungs.
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Nahar K, Gupta N, Gauvin R, Absar S, Patel B, Gupta V, Khademhosseini A, Ahsan F. In vitro, in vivo and ex vivo models for studying particle deposition and drug absorption of inhaled pharmaceuticals. Eur J Pharm Sci 2013; 49:805-18. [PMID: 23797056 DOI: 10.1016/j.ejps.2013.06.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 05/03/2013] [Accepted: 06/07/2013] [Indexed: 01/14/2023]
Abstract
Delivery of therapeutic agents via the pulmonary route has gained significant attention over the past few decades because this route of administration offers multiple advantages over traditional routes that include localized action, non-invasive nature and favorable lung-to-plasma ratio. However, assessment of post administration behavior of inhaled pharmaceuticals-such as deposition of particles over the respiratory airways, interaction with the respiratory fluid and movement across the air-blood barrier-is challenging because the lung is a very complex organs that is composed of airways with thousands of bifurcations with variable diameters. Thus, much effort has been put forward to develop models that mimic human lungs and allow evaluation of various pharmaceutical and physiological factors that influence the deposition and absorption profiles of inhaled formulations. In this review, we sought to discuss in vitro, in vivo and ex vivo models that have been extensively used to study the behaviors of airborne particles in the lungs and determine the absorption of drugs after pulmonary administration. We have provided a summary of lung cast models, cascade impactors, noninvasive imaging, intact animals, cell culture and isolated perfused lung models as tools to evaluate the distribution and absorption of inhaled particles. We have also outlined the limitations of currently used models and proposed future studies to enhance the reproducibility of these models.
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Affiliation(s)
- Kamrun Nahar
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 Coulter Drive, Amarillo, TX 79106, USA
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Son YJ, Longest PW, Tian G, Hindle M. Evaluation and modification of commercial dry powder inhalers for the aerosolization of a submicrometer excipient enhanced growth (EEG) formulation. Eur J Pharm Sci 2013; 49:390-9. [PMID: 23608613 PMCID: PMC3744372 DOI: 10.1016/j.ejps.2013.04.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/08/2013] [Accepted: 04/06/2013] [Indexed: 11/26/2022]
Abstract
The aim of this study was to evaluate and modify commercial dry powder inhalers (DPIs) for the aerosolization of a submicrometer excipient enhanced growth (EEG) formulation. The optimized device and formulation combination was then tested in a realistic in vitro mouth-throat - tracheobronchial (MT-TB) model. An optimized EEG submicrometer powder formulation, consisting of albuterol sulfate (drug), mannitol (hygroscopic excipient), l-leucine (dispersion enhancer) and poloxamer 188 (surfactant) in a ratio of 30:48:20:2 was prepared using a Büchi Nano spray dryer. The aerosolization performance of the EEG formulation was evaluated with five conventional DPIs: Aerolizer, Novolizer, HandiHaler, Exubera and Spiros. To improve powder dispersion, the HandiHaler was modified with novel mouth piece (MP) designs. The aerosol performance of each device was assessed using a next generation impactor (NGI) at airflow rates generating a pressure drop of 4 kPa across the DPI. In silico and in vitro deposition and hygroscopic growth of formulations was studied using a MT-TB airway geometry model. Both HandiHaler and Aerolizer produced high emitted doses (EDs) together with a significant submicrometer aerosol fraction. A modified HandiHaler with a MP including a three-dimensional (3D) array of rods (HH-3D) produced a submicrometer particle fraction of 38.8% with a conventional fine particle fraction (%<5 μm) of 97.3%. The mass median diameter (MMD) of the aerosol was reduced below 1 μm using this HH-3D DPI. The aerosol generated from the modified HandiHaler increased to micrometer size (2.8 μm) suitable for pulmonary deposition, when exposed to simulated respiratory conditions, with negligible mouth-throat (MT) deposition (2.6%).
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Affiliation(s)
- Yoen-Ju Son
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
| | - P. Worth Longest
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Geng Tian
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Michael Hindle
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA
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Longest PW, Son YJ, Holbrook L, Hindle M. Aerodynamic factors responsible for the deaggregation of carrier-free drug powders to form micrometer and submicrometer aerosols. Pharm Res 2013; 30:1608-27. [PMID: 23471640 DOI: 10.1007/s11095-013-1001-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 02/01/2013] [Indexed: 12/18/2022]
Abstract
PURPOSE To employ in vitro experiments combined with computational fluid dynamics (CFD) analysis to determine which aerodynamic factors were most responsible for deaggregating carrier-free powders to form micrometer and submicrometer aerosols from a capsule-based platform. METHODS Eight airflow passages were evaluated for deaggregation of the aerosol including a standard constricted tube, impaction surface, 2D mesh, inward radial jets, and newly proposed 3D grids and rod arrays. CFD simulations were implemented to evaluate existing and new aerodynamic factors for deaggregation and in vitro experiments were used to evaluate performance of each inhaler. RESULTS For the carrier-free formulation considered, turbulence was determined to be the primary deaggregation mechanism. A strong quantitative correlation was established between the mass median diameter (MMD) and newly proposed non-dimensional specific dissipation (NDSD) factor, which accounts for turbulent energy, inverse of the turbulent length scale, and exposure time. A 3D rod array design with unidirectional elements maximized NDSD and produced the best deaggregation with MMD<1 μm. CONCLUSIONS The new NDSD parameter can be used to develop highly effective dry powder inhalers like the 3D rod array that can efficiently produce submicrometer aerosols for next-generation respiratory drug delivery applications.
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Affiliation(s)
- P Worth Longest
- Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia, USA.
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Son YJ, Worth Longest P, Hindle M. Aerosolization characteristics of dry powder inhaler formulations for the excipient enhanced growth (EEG) application: effect of spray drying process conditions on aerosol performance. Int J Pharm 2013; 443:137-45. [PMID: 23313343 DOI: 10.1016/j.ijpharm.2013.01.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/14/2012] [Accepted: 01/02/2013] [Indexed: 10/27/2022]
Abstract
The aim of this study was to develop a spray dried submicrometer powder formulation suitable for the excipient enhanced growth (EEG) application. Combination particles were prepared using the Buchi Nano spray dryer B-90. A number of spray drying and formulation variables were investigated with the aims of producing dry powder formulations that were readily dispersed upon aerosolization and maximizing the fraction of submicrometer particles. Albuterol sulfate, mannitol, L-leucine, and poloxamer 188 were selected as a model drug, hygroscopic excipient, dispersibility enhancer and surfactant, respectively. Formulations were assessed by scanning electron microscopy and aerosol performance following aerosolization using an Aerolizer dry powder inhaler (DPI). In vitro drug deposition was studied using a realistic mouth-throat (MT) model. Based on the in vitro aerosolization results, the best performing submicrometer powder formulation consisted of albuterol sulfate, mannitol, L-leucine and poloxamer 188 in a ratio of 30:48:20:2, containing 0.5% solids in a water:ethanol (80:20%, v/v) solution which was spray dried at 70 °C. The submicrometer particle fraction (FPF(1 μm/ED)) of this final formulation was 28.3% with more than 80% of the capsule contents being emitted during aerosolization. This formulation also showed 4.1% MT deposition. The developed combination formulation delivered a powder aerosol developed for the EEG application with high dispersion efficiency and low MT deposition from a convenient DPI device platform.
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Affiliation(s)
- Yoen-Ju Son
- Department of Pharmaceutics, Virginia Commonwealth University, Richmond, VA, USA.
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Longest PW, Walenga RL, Son YJ, Hindle M. High-efficiency generation and delivery of aerosols through nasal cannula during noninvasive ventilation. J Aerosol Med Pulm Drug Deliv 2012; 26:266-79. [PMID: 23273243 DOI: 10.1089/jamp.2012.1006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Previous studies have demonstrated the delivery of pharmaceutical aerosols through nasal cannula and the feasibility of enhanced condensational growth (ECG) with a nasal interface. The objectives of this study were to develop a device for generating submicrometer aerosols with minimal depositional loss in the formation process and to improve aerosol delivery efficiencies through nasal cannulas. METHODS A combination of in vitro experiments and computational fluid dynamics (CFD) simulations that used the strengths of each method was applied. Aerosols were formed using a conventional mesh nebulizer, mixed with ventilation gas, and heated to produce submicrometer sizes. An improved version of the mixer and heater unit was developed based on CFD simulations, and performance was verified with experiments. Aerosol delivery was considered through a commercial large-bore adult cannula, a divided (D) design for use with ECG, and a divided and streamlined (DS) design. RESULTS The improved mixer design reduced the total deposition fraction (DF) of drug within the mixer by a factor of 3 compared with an initial version, had a total DF of approximately 10%, and produced submicrometer aerosols at flow rates of 10 and 15 L/min. Compared with the commercial and D designs for submicrometer aerosols, the DS cannula reduced depositional losses by a factor of 2-3 and retained only approximately 5% or less of the nebulized dose at all flow rates considered. For conventional-sized aerosols (3.9 and 4.7 μm), the DS device provided delivery efficiencies of approximately 80% and above at flow rates of 2-15 L/min. CONCLUSIONS Submicrometer aerosols can be formed using a conventional mesh nebulizer and delivered through a nasal cannula with total delivery efficiencies of 80-90%. Streamlining the nasal cannula significantly improved the delivery efficiency of both submicrometer and micrometer aerosols; however, use of submicrometer particles with ECG delivery resulted in overall lower depositional losses.
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Affiliation(s)
- P Worth Longest
- 1 Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, VA 23284
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Longest PW, Spence BM, Holbrook LT, Mossi KM, Son YJ, Hindle M. Production of Inhalable Submicrometer Aerosols from Conventional Mesh Nebulizers for Improved Respiratory Drug Delivery. JOURNAL OF AEROSOL SCIENCE 2012; 51:66-80. [PMID: 22707794 PMCID: PMC3374487 DOI: 10.1016/j.jaerosci.2012.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Submicrometer and nanoparticle aerosols may significantly improve the delivery efficiency, dissolution characteristics, and bioavailability of inhaled pharmaceuticals. The objective of this study was to explore the formation of submicrometer and nanometer aerosols from mesh nebulizers suitable for respiratory drug delivery using experiments and computational fluid dynamics (CFD) modeling. Mesh nebulizers were coupled with add-on devices to promote aerosol drying and the formation of submicrometer particles, as well as to control the inhaled aerosol temperature and relative humidity. Cascade impaction experiments were used to determine the initial mass median aerodynamic diameters of 0.1% albuterol aerosols produced by the AeroNeb commercial (4.69 μm) and lab (3.90 μm) nebulizers and to validate the CFD model in terms of droplet evaporation. Through an appropriate selection of flow rates, nebulizers, and model drug concentrations, submicrometer and nanometer aerosols could be formed with the three devices considered. Based on CFD simulations, a wire heated design was shown to overheat the airstream producing unsafe conditions for inhalation if the aerosol was not uniformly distributed in the tube cross-section or if the nebulizer stopped producing droplets. In comparison, a counter-flow heated design provided sufficient thermal energy to produce submicrometer particles, but also automatically limited the maximum aerosol outlet temperature based on the physics of heat transfer. With the counter-flow design, submicrometer aerosols were produced at flow rates of 5, 15, and 30 LPM, which may be suitable for various forms of oral and nasal aerosol delivery. Thermodynamic conditions of the aerosol stream exiting the counter-flow design were found be in a range of 21-45 °C with relative humidity greater than 40% in some cases, which was considered safe for direct inhalation and advantageous for condensational growth delivery.
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Affiliation(s)
- P. Worth Longest
- Department of Mechanical Engineering Virginia Commonwealth University, Richmond, VA
- Department of Pharmaceutics Virginia Commonwealth University, Richmond, VA
| | - Benjamin M. Spence
- Department of Mechanical Engineering Virginia Commonwealth University, Richmond, VA
| | - Landon T. Holbrook
- Department of Mechanical Engineering Virginia Commonwealth University, Richmond, VA
| | - Karla M. Mossi
- Department of Mechanical Engineering Virginia Commonwealth University, Richmond, VA
| | - Yoen-Ju Son
- Department of Pharmaceutics Virginia Commonwealth University, Richmond, VA
| | - Michael Hindle
- Department of Pharmaceutics Virginia Commonwealth University, Richmond, VA
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Longest PW, Tian G, Li X, Son YJ, Hindle M. Performance of combination drug and hygroscopic excipient submicrometer particles from a softmist inhaler in a characteristic model of the airways. Ann Biomed Eng 2012; 40:2596-610. [PMID: 22820981 DOI: 10.1007/s10439-012-0616-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/04/2012] [Indexed: 12/20/2022]
Abstract
Excipient enhanced growth (EEG) of inhaled submicrometer pharmaceutical aerosols is a recently proposed method intended to significantly reduce extrathoracic deposition and improve lung delivery. The objective of this study was to evaluate the size increase of combination drug and hygroscopic excipient particles in a characteristic model of the airways during inhalation using both in vitro experiments and computational fluid dynamic (CFD) simulations. The airway model included a characteristic mouth-throat (MT) and upper tracheobronchial (TB) region through the third bifurcation and was enclosed in a chamber geometry used to simulate the thermodynamic conditions of the lungs. Both in vitro results and CFD simulations were in close agreement and indicated that EEG delivery of combination submicrometer particles could nearly eliminate MT deposition for inhaled pharmaceutical aerosols. Compared with current inhalers, the proposed delivery approach represents a 1-2 order of magnitude reduction in MT deposition. Transient inhalation was found to influence the final size of the aerosol based on changes in residence times and relative humidity values. Aerosol sizes following EEG when exiting the chamber (2.75-4.61 μm) for all cases of initial submicrometer combination particles were equivalent to or larger than many conventional pharmaceutical aerosols that frequently have MMADs in the range of 2-3 μm.
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Affiliation(s)
- P Worth Longest
- Department of Mechanical Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, VA 23284-3015, USA.
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