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Dobson DP, Saggu M, Pellett JD, Tso J. A Novel Technique to Assess Drug Substance Particle Size in a Complex Inhaled Formulation. J Pharm Sci 2023; 112:2385-2388. [PMID: 37422282 DOI: 10.1016/j.xphs.2023.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/10/2023]
Abstract
Dry powder inhalers, comprising an active pharmaceutical ingredient (API) and carrier excipients, are often used in the delivery of pulmonary drugs. The stability of the API particle size within a formulation blend is a critical attribute for aerodynamic performance but can be challenging to measure. The presence of excipients, typically at concentrations much higher than API, makes measurement by laser diffraction very difficult. This work introduces a novel laser diffraction approach that takes advantage of solubility differences between the API and excipients. The method allows insight into the understanding of drug loading effects on API particle stability of the drug product. Lower drug load formulations show better particle size stability compared with high drug load formulations, likely due to reduced cohesive interactions.
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Affiliation(s)
- Daniel P Dobson
- Genentech, 1 DNA Way, South San Francisco, CA 94080, United States.
| | - Miguel Saggu
- Genentech, 1 DNA Way, South San Francisco, CA 94080, United States
| | | | - Jerry Tso
- Genentech, 1 DNA Way, South San Francisco, CA 94080, United States; Ideaya Biosciences, 7000 Shoreline Ct #350, South San Francisco, CA 94080, United States
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2
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Nano-enabled agglomerates and compact: Design aspects of challenges. Asian J Pharm Sci 2023; 18:100794. [PMID: 37035131 PMCID: PMC10074506 DOI: 10.1016/j.ajps.2023.100794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 02/24/2023] Open
Abstract
Nanoscale medicine confers passive and active targeting potential. The development of nanomedicine is however met with processing, handling and administration hurdles. Excessive solid nanoparticle aggregation and caking result in low product yield, poor particle flowability and inefficient drug administration. These are overcome by converting the nanoparticles into a microscale dosage form via agglomeration or compaction techniques. Agglomeration and compaction nonetheless predispose the nanoparticles to risks of losing their nanogeometry, surface composition or chemistry being altered and negating biological performance. This study reviews risk factors faced during agglomeration and compaction that could result in these changes to nanoparticles. The potential risk factors pertain to materials choice in nanoparticle and microscale dosage form development, and their interplay effects with process temperature, physical forces and environmental stresses. To render the physicochemical and biological behaviour of the nanoparticles unaffected by agglomeration or compaction, modes to modulate the interplay effects of material and formulation with processing and environment variables are discussed.
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Design and Characterization of Atorvastatin Dry Powder Formulation as a potential Lung Cancer Treatment. Saudi Pharm J 2022; 29:1449-1457. [PMID: 35002383 PMCID: PMC8720807 DOI: 10.1016/j.jsps.2021.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 11/05/2021] [Indexed: 11/20/2022] Open
Abstract
Lung cancer is the leading cause of cancer death. Many studies have shown the beneficial effects of Atorvastatin in decreasing the mortality risk and improving survival among patients with lung cancer. This research paper focuses on improving AVT cytotoxic activity and cellular uptake by developing mannitol microcarriers as a promising drug delivery system for lung cancer treatment and, studying the impact of improving inhalation deposition on the delivery and Dry Powder formulations efficiency. The AVT loaded mannitol (AM) microparticles (AVT-AM) formulation was prepared by spray drying and characterized for its physicochemical properties and aerodynamic deposition. The results revealed that the AVT-AM formulation has good flow properties and aerosol deposition with a particle size of 3418 nm ± 26.86. The formulation was also assessed in vitro for cytotoxicity effects (proliferation, apoptosis, and cell cycle progression) on A549 human lung adenocarcinoma. Compared with free AVT, the AVT-AM formulation has significantly higher cellular uptake and anti-cancer properties by disrupting cell cycle progression via either apoptosis or cell cycle arrest in the G2/M phase. This study shows that AVT loaded mannitol microcarriers may provide a potentially effective and sustained pulmonary drug delivery for lung cancer treatment.
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Benke E, Winter C, Szabó-Révész P, Roblegg E, Ambrus R. The effect of ethanol on the habit and in vitro aerodynamic results of dry powder inhalation formulations containing ciprofloxacin hydrochloride. Asian J Pharm Sci 2021; 16:471-482. [PMID: 34703496 PMCID: PMC8520052 DOI: 10.1016/j.ajps.2021.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 12/02/2022] Open
Abstract
In the case of dry powder inhalation systems (DPIs), the development of carrier-free formulations has gained increased attention. Thereby, spray-drying is a promising technology and is widely used to produce carrier-free DPIs. Numerous works have been published about the co-spray-drying of active ingredients with various solid excipients and their effect on the physicochemical characteristics and aerodynamic properties of the formulations. However, only a few studies have been reported about the role of the solvents used in the stock solutions of spray-dried formulations. In the present work, DPI microcomposites containing ciprofloxacin hydrochloride were prepared by spray-drying in the presence of different ethanol concentrations. The work expresses the roughness, depth and width of the dimples for particle size as a novel calculation possibility, and as a correlation between the MMAD/D0.5 ratio and correlating it with cohesion work, these new terms and correlations have not been published – to the best of our knowledge – which has resulted in gap-filling findings. As a result, different proportions of solvent mixtures could be interpreted and placed in a new perspective, in which the influence of different concentrations of ethanol on the habit of the DPI formulations, and thus on in vitro aerodynamic results. Based on these, it became clear why we obtained the best in vitro aerodynamic results for DPI formulation containing 30% ethanol in the stock solution.
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Affiliation(s)
- Edit Benke
- Institute of Pharmaceutical Technology and Regulatory Affairs, University of Szeged, Szeged H-6720, Hungary
| | - Christina Winter
- Institute of Pharmaceutical Sciences, Pharmaceutical Technology and Biopharmacy, University of Graz, Universitätsplatz 1, Graz A-8010, Austria
- Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, Graz A-8010, Austria
| | - Piroska Szabó-Révész
- Institute of Pharmaceutical Technology and Regulatory Affairs, University of Szeged, Szeged H-6720, Hungary
| | - Eva Roblegg
- Institute of Pharmaceutical Sciences, Pharmaceutical Technology and Biopharmacy, University of Graz, Universitätsplatz 1, Graz A-8010, Austria
- Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 13, Graz A-8010, Austria
| | - Rita Ambrus
- Institute of Pharmaceutical Technology and Regulatory Affairs, University of Szeged, Szeged H-6720, Hungary
- Corresponding author.
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Focaroli S, Jiang G, O’Connell P, Fahy JV, Healy AM. The Use of a Three-Fluid Atomising Nozzle in the Production of Spray-Dried Theophylline/Salbutamol Sulphate Powders Intended for Pulmonary Delivery. Pharmaceutics 2020; 12:E1116. [PMID: 33233520 PMCID: PMC7699582 DOI: 10.3390/pharmaceutics12111116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/02/2022] Open
Abstract
The aim of this study was to investigate the use of a three-fluid atomising nozzle in a lab-scale spray dryer for the production of dry powders intended for pulmonary delivery. Powders were composed of salbutamol sulphate and theophylline in different weight ratios. The three-fluid nozzle technology enabled powders containing a high theophylline content to be obtained, overcoming the problems associated with its relatively low solubility, by pumping two separate feed solutions (containing the two different active pharmaceutical ingredients (APIs)) into the spray dryer via two separate nozzle channels at different feed rates. The final spray-dried products were characterized in terms of morphology, solid-state properties and aerosolization performance, and were compared with an equivalent formulation prepared using a standard two-fluid atomising nozzle. Results confirmed that most of the powders made using the three-fluid atomising nozzle met the required standards for a dry powder inhaler formulation in terms of physical characteristics; however, aerosolization characteristics require improvement if the powders are to be considered suitable for pulmonary delivery.
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Affiliation(s)
- Stefano Focaroli
- School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin 2 D02, Ireland; (G.J.); (P.O.); (A.-M.H.)
| | - Guannan Jiang
- School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin 2 D02, Ireland; (G.J.); (P.O.); (A.-M.H.)
| | - Peter O’Connell
- School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin 2 D02, Ireland; (G.J.); (P.O.); (A.-M.H.)
| | - John V. Fahy
- Division of Pulmonary and Critical Care Medicine, Department of Medicine and Cardiovascular Research Institute, Health Sciences East, UCSF, 513 Parnassus Avenue, San Francisco, CA 94143, USA;
| | - Anne-Marie Healy
- School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin 2 D02, Ireland; (G.J.); (P.O.); (A.-M.H.)
- SSPC The SFI Research Centre for Pharmaceuticals, School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2 D02, Ireland
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Gamal A, Saeed H, Sayed OM, Kharshoum RM, Salem HF. Proniosomal Microcarriers: Impact of Constituents on the Physicochemical Properties of Proniosomes as a New Approach to Enhance Inhalation Efficiency of Dry Powder Inhalers. AAPS PharmSciTech 2020; 21:156. [PMID: 32449087 DOI: 10.1208/s12249-020-01705-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/03/2020] [Indexed: 02/08/2023] Open
Abstract
Proniosomes are free-flowing systems with coating carriers, which developed as a method for improving the drug flow and pulmonary delivery. Extensive research on proniosomes was done to enhance the dry powder inhalers (DPI)'s inhalation performance. This research aimed at studying the impact of lactose-mannitol mixture additives on the proniosome's physicochemical properties as a method for improving the inhalation efficiency of DPI. Vismodegib has been employed as a compound model. Box-Behnken design has been employed to prepare different proniosomes formulae by incorporating various (A) span 60 concentrations, (B) lactose concentrations and (C) mannitol: total carrier mixture. The measured responses were vesicle size (R1), %release (R2), Carr's index (R3) and %recovery (R4). The results displayed that R1 and R4 were significantly antagonistic to C and significantly synergistic to both A and B while R2 and R3 were significantly synergistic to C and significantly antagonistic to both A and B. The optimal formula was selected for its aerodynamic behaviour, cytotoxic activity and bioavailability assessment. The optimal formula resulted in better Vismodegib lung deposition, cytotoxic activity and relative bioavailability. This novel formula could be a promising carrier for sustained delivery of drugs via the pulmonary route.
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Malamatari M, Somavarapu S, Kachrimanis K, Bloxham M, Taylor KMG, Buckton G. Preparation of theophylline inhalable microcomposite particles by wet milling and spray drying: The influence of mannitol as a co-milling agent. Int J Pharm 2017; 514:200-211. [PMID: 27863663 DOI: 10.1016/j.ijpharm.2016.06.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 11/16/2022]
Abstract
Inhalable theophylline particles with various amounts of mannitol were prepared by combining wet milling in isopropanol followed by spray drying. The effect of mannitol as a co-milling agent on the micromeritic properties, solid state and aerosol performance of the engineered particles was investigated. Crystal morphology modelling and geometric lattice matching calculations were employed to gain insight into the intermolecular interactions that may influence the mechanical properties of theophylline and mannitol. The addition of mannitol facilitated the size reduction of the needle-like crystals of theophylline and also their assembly in microcomposites by forming a porous structure of mannitol nanocrystals wherein theophylline particles are embedded. The microcomposites were found to be in the same crystalline state as the starting material(s) ensuring their long-term physical stability upon storage. Incorporation of mannitol resulted in microcomposite particles with smaller size, more spherical shape and increased porosity. The aerosol performance of the microcomposites was markedly enhanced compared to the spray-dried suspension of theophylline wet milled without mannitol. Overall, wet co-milling with mannitol in an organic solvent followed by spray drying may be used as a formulation approach for producing respirable particles of water-soluble drugs or drugs that are prone to crystal transformation in an aqueous environment (i.e. formation of hydrates).
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Affiliation(s)
- Maria Malamatari
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | | | - Kyriakos Kachrimanis
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Mark Bloxham
- GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK
| | - Kevin M G Taylor
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Graham Buckton
- UCL School of Pharmacy, 29-39 Brunswick Square, London, WC1N 1AX, UK.
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8
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Mehta P. Dry Powder Inhalers: A Focus on Advancements in Novel Drug Delivery Systems. JOURNAL OF DRUG DELIVERY 2016; 2016:8290963. [PMID: 27867663 PMCID: PMC5102732 DOI: 10.1155/2016/8290963] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/25/2016] [Accepted: 10/09/2016] [Indexed: 12/20/2022]
Abstract
Administration of drug molecules by inhalation route for treatment of respiratory diseases has the ability to deliver drugs, hormones, nucleic acids, steroids, proteins, and peptides, particularly to the site of action, improving the efficacy of the treatment and consequently lessening adverse effects of the treatment. Numerous inhalation delivery systems have been developed and studied to treat respiratory diseases such as asthma, COPD, and other pulmonary infections. The progress of disciplines such as biomaterials science, nanotechnology, particle engineering, molecular biology, and cell biology permits further improvement of the treatment capability. The present review analyzes modern therapeutic approaches of inhaled drugs with special emphasis on novel drug delivery system for treatment of various respiratory diseases.
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Affiliation(s)
- Piyush Mehta
- Dry Powder Inhaler Lab, Respiratory Formulations, Cipla R & D, LBS Road, Vikhroli (W), Mumbai, Maharashtra 400079, India
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Salem HF, Kharshoum RM, Abdel Hakim LF, Abdelrahim ME. Edge activators and a polycationic polymer enhance the formulation of porous voriconazole nanoagglomerate for the use as a dry powder inhaler. J Liposome Res 2016; 26:324-35. [PMID: 26872552 DOI: 10.3109/08982104.2016.1140182] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Voriconazole has both low aqueous solubility and stability. We hypothesize that designing voriconazole in the form of a nano powder inhaler at a geometric diameter within 1-5 μm will enhance its stability and solubility. Therefore, we prepared nanoagglomerates of voriconazole which will collapse in the lungs to reform the nanoparticles. METHOD The nanoparticles were formulated using both stearic acid and sodium deoxycholate as edge activators. Osmogenic polycation polyethyleneimine (PEI) was used to form agglomerates of controllable size. RESULTS Voriconazole nanoparticles and agglomerates showed a significant higher cumulative drug release than the pure powder (p < 0.05) with R(2 )=( )0.95. Small-sized particles were formed (353 nm), while their zeta potential was -30.7 mV. The agglomerates were 2.7 μm in size and their zeta potential was -20.9 mV. The formation of porous agglomerates was confirmed using a transmission electron microscope. Cascade impactor was used to evaluate the aerodynamic properties of the nanoparticles and the agglomerates. The aerodynamic characterization of the nanoparticles and the agglomerates resulted in a significant smaller mass median aerodynamic diameter (MMAD) (p < 0.05) and higher fine particle dose (FPD) (p < 0.01), fine particle fraction (FPF) (p < 0.01), and total emitted dose (TED) (p < 0.01) than the pure powder. CONCLUSION The results suggest that using the combination of edge activators and diluted polycationic polymer solution provides porous voriconazole nanoagglomerates in a respirable range, which is proved successful in enhancing both the deposition and the dissolution of water insoluble-drugs in the lung.
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Affiliation(s)
- Heba F Salem
- a Department of Pharmaceutics and Industrial Pharmacy and
| | | | | | - Mohamed E Abdelrahim
- b Department of Clinical Pharmacy , Faculty of Pharmacy, The University of Beni-Suef , Beni-Suef , Egypt
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Malamatari M, Somavarapu S, Taylor KM, Buckton G. Solidification of nanosuspensions for the production of solid oral dosage forms and inhalable dry powders. Expert Opin Drug Deliv 2016; 13:435-50. [DOI: 10.1517/17425247.2016.1142524] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Recent advances in the engineering of nanosized active pharmaceutical ingredients: Promises and challenges. Adv Colloid Interface Sci 2016; 228:71-91. [PMID: 26792017 DOI: 10.1016/j.cis.2015.11.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/28/2015] [Accepted: 11/18/2015] [Indexed: 11/22/2022]
Abstract
The advances in the field of nanotechnology have revolutionized the field of delivery of poorly soluble active pharmaceutical ingredients (APIs). Nanosized formulations have been extensively investigated to achieve a rapid dissolution and therefore pharmacokinetic properties similar to those observed in solutions. The present review outlines the recent advances, promises and challenges of the engineering nanosized APIs. The principles, merits, demerits and applications of the current 'bottom-up' and 'top-down' technologies by which the state of the art nanosized APIs can be produced were described. Although the number of research reports on the nanoparticle engineering topic has been growing in the last decade, the challenge is to take numerous research outcomes and convert them into strategies for the development of marketable products.
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Abdelbary AA, Al-mahallawi AM, Abdelrahim ME, Ali AMA. Preparation, optimization, and in vitro simulated inhalation delivery of carvedilol nanoparticles loaded on a coarse carrier intended for pulmonary administration. Int J Nanomedicine 2015; 10:6339-53. [PMID: 26491298 PMCID: PMC4608592 DOI: 10.2147/ijn.s91631] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Carvedilol (CAR) is a potent antihypertensive drug but has poor oral bioavailability (24%). A nanosuspension suitable for pulmonary delivery to enhance bioavailability and bypass first-pass metabolism of CAR could be advantageous. Accordingly, the aim of this work was to prepare CAR nanosuspensions and to use artificial neural networks associated with genetic algorithm to model and optimize the formulations. The optimized nanosuspension was lyophilized to obtain dry powder suitable for inhalation. However, respirable particles must have a diameter of 1-5 µm in order to deposit in the lungs. Hence, mannitol was used during lyophilization for cryoprotection and to act as a coarse carrier for nanoparticles in order to deliver them into their desired destination. The bottom-up technique was adopted for nanosuspension formulation using Pluronic stabilizers (F127, F68, and P123) combined with sodium deoxycholate at 1:1 weight ratio, at three levels with two drug loads and two aqueous to organic phase volume ratios. The drug crystallinity was studied using differential scanning calorimetry and powder X-ray diffractometry. The in vitro emitted doses of CAR were evaluated using a dry powder inhaler sampling apparatus and the aerodynamic characteristics were evaluated using an Andersen MKII cascade impactor. The artificial neural networks results showed that Pluronic F127 was the optimum stabilizer based on the desired particle size, polydispersity index, and zeta potential. Results of differential scanning calorimetry combined with powder X-ray diffractometry showed that CAR crystallinity was observed in the lyophilized nanosuspension. The aerodynamic characteristics of the optimized lyophilized nanosuspension demonstrated significantly higher percentage of total emitted dose (89.70%) and smaller mass median aerodynamic diameter (2.80 µm) compared with coarse drug powder (73.60% and 4.20 µm, respectively). In summary, the above strategy confirmed the applicability of formulating CAR in the form of nanoparticles loaded on a coarse carrier suitable for inhalation delivery.
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Affiliation(s)
- Aly A Abdelbary
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Abdulaziz M Al-mahallawi
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | | | - Ahmed M A Ali
- Department of Pharmaceutics, Faculty of Pharmacy, Beni Suef University, Beni Suef, Egypt ; Department of Pharmaceutics, Faculty of Pharmacy, Taif University, Taif, Saudi Arabia
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Duret C, Wauthoz N, Sebti T, Vanderbist F, Amighi K. New inhalation-optimized itraconazole nanoparticle-based dry powders for the treatment of invasive pulmonary aspergillosis. Int J Nanomedicine 2012; 7:5475-89. [PMID: 23093903 PMCID: PMC3477927 DOI: 10.2147/ijn.s34091] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Itraconazole (ITZ) dry powders for inhalation (DPI) composed of nanoparticles (NP) embedded in carrier microparticles were prepared and characterized. METHODS DPIs were initially produced by reducing the ITZ particle size to the nanometer range using high-pressure homogenization with tocopherol polyethylene 1000 succinate (TPGS, 10% w/w ITZ) as a stabilizer. The optimized nanosuspension and the initial microsuspension were then spray-dried with different proportions of or in the absence of mannitol and/or sodium taurocholate. DPI characterization was performed using scanning electron microscopy for morphology, laser diffraction to evaluate the size-reduction process, and the size of the dried NP when reconstituted in aqueous media, impaction studies using a multistage liquid impactor to determine the aerodynamic performance and fine-particle fraction that is theoretically able to reach the lung, and dissolution studies to determine the solubility of ITZ. RESULTS Scanning electron microscopy micrographs showed that the DPI particles were composed of mannitol microparticles with embedded nano- or micro-ITZ crystals. The formulations prepared from the nanosuspension exhibited good flow properties and better fine-particle fractions, ranging from 46.2% ± 0.5% to 63.2% ± 1.7% compared to the 23.1% ± 0.3% that was observed with the formulation produced from the initial microsuspension. Spray-drying affected the NP size by inducing irreversible aggregation, which was able to be minimized by the addition of mannitol and sodium taurocholate before the drying procedure. The ITZ NP-based DPI considerably increased the ITZ solubility (58 ± 2 increased to 96 ± 1 ng/mL) compared with that of raw ITZ or an ITZ microparticle-based DPI (<10 ng/mL). CONCLUSION Embedding ITZ NP in inhalable microparticles is a very effective method to produce DPI formulations with optimal aerodynamic properties and enhanced ITZ solubility. These formulations could be applied to other poorly water-soluble drugs and could be a very effective alternative for treating invasive pulmonary aspergillosis.
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Affiliation(s)
- Christophe Duret
- Laboratoire de Pharmacie Galénique et de Biopharmacie, Université Libre de Bruxelles, Brussels, Belgium.
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