1
|
Kondo K, Ohta S, Niwa T. Preparation of sustained-release tablets using a solventless-mixing tablet coating technique: Particle design of dry ammonioalkyl methacrylate copolymer latex with high coating performance using sodium lauryl sulfate. Eur J Pharm Biopharm 2023:S0939-6411(23)00115-7. [PMID: 37172695 DOI: 10.1016/j.ejpb.2023.05.001] [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: 03/31/2023] [Revised: 04/22/2023] [Accepted: 05/01/2023] [Indexed: 05/15/2023]
Abstract
The aim of this study was to produce sustained-release tablets by V-shaped blending of polymer and tablets without using solvents or heating, and we investigated the design of polymer particles with high coating performance by modifying the structure of the particles using sodium lauryl sulfate. Dry-latex particles of ammonioalkyl methacrylate copolymer were prepared by adding the surfactant into aqueous latex, followed by freeze drying. The resulting dry latex was mixed with tablets (1:10) using a blender and the resulting coated tablets were characterized. Tablet coating by the dry latex was promoted as the weight ratio of surfactant to polymer increased. At a surfactant ratio of 5%, deposition of the dry latex was most effective and the resulting coated tablets (annealed at 60 °C/75%RH for 6 h) exhibited sustained-release characteristics over a period of 2 h. The addition of SLS prevented coagulation of colloidal polymer in the freeze drying, resulting in a loose-structured dry latex. This latex was easily pulverized by V-shaped blending with tablets and the resulting fine particles with high adhesiveness were deposited on the tablets. However, at a surfactant ratio of 10%, the coating of dry latex decreased due to reduced adhesiveness.
Collapse
Affiliation(s)
- Keita Kondo
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan.
| | - Sayaka Ohta
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Toshiyuki Niwa
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| |
Collapse
|
2
|
Oral colon delivery platform based on a novel combination approach: Design concept and preliminary evaluation. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
3
|
Rongthong T, Pongjanyakul T. Quaternary polymethacrylate−magnesium aluminum silicate film formers: Stability studies for tablet coatings. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
4
|
Characterization of transport mechanisms for controlled release polymer membranes using focused ion beam scanning electron microscopy image-based modelling. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2020.102136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
5
|
Ciprofloxacin self-dissolvable Soluplus based polymeric films: a novel proposal to improve the management of eye infections. Drug Deliv Transl Res 2021; 11:608-625. [PMID: 33528829 PMCID: PMC7852484 DOI: 10.1007/s13346-020-00887-1] [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] [Accepted: 12/14/2020] [Indexed: 01/31/2023]
Abstract
Infections of the eye are among the leading causes of vision impairment and vision loss worldwide. The ability of a drug to access the anterior parts of the eye is negligible after systemic administration. Effective drug delivery to the eye is a major challenge due to the presence of protective mechanisms and physiological barriers that result in low ocular availability after topical application. The main purpose of this work was the improvement of the corneal and conjunctival permeation of the antibiotic Ciprofloxacin, a wide spectrum antibiotic used for the most common eye infection, using a self-dissolving polymeric film. Films were prepared by the solvent casting technique, using polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer (Soluplus), polyvynyl alcohol, and propylene glycol. Films were homogeneous in drug content and thickness, as demonstrated by adapting the Swiss Roll technique followed by microscopy observation. These films proved in vitro to control the release of the Ciprofloxacin. Ex vivo permeability studies using Franz diffusion cells and porcine cornea and sclera showed an effective permeability of the drug without inducing irritation of the tissues. Films swelled in contact with artificial tears forming an in situ gel over 20 min, which will improve drug contact and reduce the need of multiple dosing. The antibiotic activity was also tested in vitro in five types of bacterial cultures, assuring the pharmacological efficacy of the films. The developed films are a promising drug delivery system to topically treat or prevent ocular infections.
Collapse
|
6
|
Kim B, Woo YA. Optimization of in-line near-infrared measurement for practical real time monitoring of coating weight gain using design of experiments. Drug Dev Ind Pharm 2020; 47:72-82. [PMID: 33325254 DOI: 10.1080/03639045.2020.1862166] [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: 10/22/2022]
Abstract
This study was conducted to develop an in-line near-infrared (NIR) spectroscopy approach that allows real time quantitative analysis of the coating weight gain on a moving tablet surface during a coating process where talc is used. A holder directly inserting a diffuse reflectance probe into a coating pan was designed, and the optimal measurement conditions were identified using the design of experiments (DoE). The surface of the probe was kept clean of coating droplets at a maximum distance between the probe and the holder of 272.5 mm, leading to the acquisition of accurate spectral data. Under this condition, partial least squares regression (PLSR) was developed using the spectra from 7197 to 6233 cm-1, which covers the specific peaks for the core tablet and the coating solution. Under the same conditions, least squares regression (LSR) was developed using the univariate predictive analysis of the single absorption spectrum of talc at 7181 cm-1. In a comparison of the accuracy of the two models, PLSR was found to be more accurate as a result of testing the significance of differences between these distributions in terms of the root mean square errors of prediction (RMSEP) using a randomization t-test. Additionally, it confirmed that the predicted weight gain using NIR spectroscopy was correlated with the coating thickness measured using micro-CT. In conclusion, this study developed an in-line NIR measurement approach for the real-time monitoring of the coating weight gain of tablets and optimized the conditions by evaluating the effect of various factors.
Collapse
Affiliation(s)
- Byungsuk Kim
- Chong Kun Dang Pharm., Cheonan, Republic of Korea
| | - Young-Ah Woo
- Chong Kun Dang Pharm., Cheonan, Republic of Korea
| |
Collapse
|
7
|
Moisture barrier films for herbal medicines fabricated by electrostatic dry coating with ultrafine powders. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2020.03.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Yang Z, Craig DQM. Monitoring film coalescence from aqueous polymeric dispersions using atomic force microscopy: Surface topographic and nano-adhesion studies. Asian J Pharm Sci 2020; 15:104-111. [PMID: 32175022 PMCID: PMC7066041 DOI: 10.1016/j.ajps.2018.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/14/2018] [Accepted: 09/28/2018] [Indexed: 11/03/2022] Open
Abstract
The aim of the investigation was to develop the use of topographic and nano-adhesion atomic force microscopy (AFM) studies as a means of monitoring the coalescence of latex particles within films produced from a pharmaceutically relevant aqueous dispersion (EudragitⓇNE30D). Films were prepared via spin coating and analysed using AFM, initially via tapping mode for topographic assessment followed by force-distance measurements which allowed assessment of site-specific adhesion. The results showed that colloidal particles were clearly observed topographically in freshly prepared samples, with coalescence detected on curing via the disappearance of discernible surface features and a decrease in roughness indices. The effects of temperature and humidity on film curing were also studied, with the former having the most pronounced effect. AFM force measurements showed that the variation in adhesive force reduced with increasing curing time, suggesting a novel method of quantifying the rate of film formation upon curing. It was concluded that the AFM methods outlined in this study may be used as a means of qualitatively and quantitatively monitoring the curing of pharmaceutical films as a function of time and other variables, thereby facilitating rational design of curing protocols.
Collapse
Affiliation(s)
- Ziyi Yang
- School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Duncan Q M Craig
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N1AX, UK
| |
Collapse
|
9
|
Hu M, Zhu Z, Wu Y, Meng Q, Luo J, Wang H. Exploring the Potential of Hydrophilic Matrix Combined with Insoluble Film Coating: Preparation and Evaluation of Ambroxol Hydrochloride Extended Release Tablets. AAPS PharmSciTech 2020; 21:93. [PMID: 32076885 DOI: 10.1208/s12249-020-1628-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 01/22/2020] [Indexed: 11/30/2022] Open
Abstract
To explore the potential utility of combination of hydrophilic matrix with membrane-controlled technology, the present study prepared tablets of a water-soluble model drug (ambroxol hydrochloride), through process of direct compression and spray coating. Single-factor experiments were accomplished to optimize the formulation. In vivo pharmacokinetics was then performed to evaluate the necessity and feasibility of further development of this simple process and low-cost approach. Various release rates could be easily obtained by adjusting the viscosity and amount of hypromellose, pore-former ratios in coating dispersions and coating weight gains. Dissolution profiles of coated tablets displayed initial delay, followed by near zero-order kinetics. The pharmacokinetic study of different formulations showed that lag time became longer as the permeability of coating membrane decreased, which was consistent with the in vitro drug release trend. Besides, in vitro/in vivo correlation study indicated that coated tablets exhibited a good correlation between in vitro release and in vivo absorption. The results, therefore, demonstrated that barrier-membrane-coated matrix formulations were extremely promising for further application in industrialization and commercialization.
Collapse
|
10
|
Rongthong T, Sungthongjeen S, Siepmann F, Siepmann J, Pongjanyakul T. Eudragit RL-based film coatings: How to minimize sticking and adjust drug release using MAS. Eur J Pharm Biopharm 2020; 148:126-133. [PMID: 31982576 DOI: 10.1016/j.ejpb.2020.01.011] [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] [Received: 10/28/2019] [Revised: 01/14/2020] [Accepted: 01/20/2020] [Indexed: 11/26/2022]
Abstract
Polymeric film coatings based on quaternary polymethacrylates (QPMs, e.g. Eudragits®) are frequently used for controlled release applications. However, their considerable sticking tendency is a major drawback in practice. In this study, different amounts of magnesium aluminum silicate (MAS) were added to the film coatings in order to overcome this hurdle. MAS is negatively charged and can electrostatically interact with the positively charged QPM. Different types of tablet cores were coated with aqueous Eudragit® RL 30D dispersions, optionally containing varying amounts of MAS. Dynamic changes in the wet mass of the systems as well as drug release upon exposure to 0.1 M HCl and phosphate buffer pH 6.8 were monitored. Propranolol HCl, acetaminophen, and diclofenac sodium were used as cationic, nonionic and anionic model drugs. The tablets were optionally cured for 12 h at 45 or 60 °C. Importantly, the addition of MAS to aqueous Eudragit® RL 30D dispersion substantially reduced the films' stickiness and led to stable inner coating structures, even without curing. Desired drug release rates can be adjusted by varying the QPM:MAS ratio and coating level.
Collapse
Affiliation(s)
- Thitiphorn Rongthong
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Srisagul Sungthongjeen
- Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 65000, Thailand
| | | | | | - Thaned Pongjanyakul
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand; Biomaterials for Pharmaceutical Formulation and Drug Delivery, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
| |
Collapse
|
11
|
Yang Q, Yuan F, Xu L, Yan Q, Yang Y, Wu D, Guo F, Yang G. An Update of Moisture Barrier Coating for Drug Delivery. Pharmaceutics 2019; 11:pharmaceutics11090436. [PMID: 31480542 PMCID: PMC6781284 DOI: 10.3390/pharmaceutics11090436] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 02/03/2023] Open
Abstract
Drug hydrolytic degradation, caused by atmospheric and inherent humidity, significantly reduces the therapeutic effect of pharmaceutical solid dosages. Moisture barrier film coating is one of the most appropriate and effective approaches to protect the active pharmaceutical ingredients (API) from hydrolytic degradation during the manufacturing process and storage. Coating formulation design and process control are the two most commonly used strategies to reduce water vapor permeability to achieve the moisture barrier function. The principles of formulation development include designing a coating formulation with non-hygroscopic/low water activity excipients, and formulating the film-forming polymers with the least amount of inherent moisture. The coating process involves spraying organic or aqueous coating solutions made of natural or synthetic polymers onto the surface of the dosage cores in a drum or a fluid bed coater. However, the aqueous coating process needs to be carefully controlled to prevent hydrolytic degradation of the drug due to the presence of water during the coating process. Recently, different strategies have been designed and developed to effectively decrease water vapor permeability and improve the moisture barrier function of the film. Those strategies include newly designed coating formulations containing polymers with optimized functionality of moisture barrier, and newly developed dry coating processes that eliminate the usage of organic solvent and water, and could potentially replace the current solvent and aqueous coatings. This review aims to summarize the recent advances and updates in moisture barrier coatings.
Collapse
Affiliation(s)
- Qingliang Yang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Feng Yuan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
| | - Lei Xu
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
| | - Qinying Yan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yan Yang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Danjun Wu
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Fangyuan Guo
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Gensheng Yang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, China.
- Research Institute of Pharmaceutical Particle Technology, Zhejiang University of Technology, Hangzhou 310014, China.
| |
Collapse
|
12
|
Speer I, Lenhart V, Preis M, Breitkreutz J. Prolonged release from orodispersible films by incorporation of diclofenac-loaded micropellets. Int J Pharm 2019; 554:149-160. [DOI: 10.1016/j.ijpharm.2018.11.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/04/2018] [Accepted: 11/05/2018] [Indexed: 11/30/2022]
|
13
|
Thapa P, Thapa R, Choi DH, Jeong SH. Effects of pharmaceutical processes on the quality of ethylcellulose coated pellets: Quality by design approach. POWDER TECHNOL 2018. [DOI: 10.1016/j.powtec.2018.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
14
|
Demiri V, Stranzinger S, Rinner P, Piller M, Sacher S, Lingitz J, Khinast J, Salar-Behzadi S. Gluing Pills Technology: A novel route to multilayer tablet manufacturing. Int J Pharm 2018; 548:672-681. [DOI: 10.1016/j.ijpharm.2018.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 11/16/2022]
|
15
|
Li Y, Wurster DE. The Effects of Curing and Casting Methods on the Physicochemical Properties of Polymer Films. AAPS PharmSciTech 2018; 19:2740-2749. [PMID: 29978291 DOI: 10.1208/s12249-018-1113-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/20/2018] [Indexed: 11/30/2022] Open
Abstract
Most film coatings in the pharmaceutical industry are prepared using organic solvents or aqueous solvents. Due to different film-formation mechanisms, their properties are significantly different from each other. Curing can alter the microstructure of films by improving the coalescence of polymer particles for aqueous dispersion-based films or accelerating macromolecule relaxation for organic solvent-based films. The aim of this study was to investigate the effects of preparation methods and curing on the physicochemical properties of Kollicoat® SR30D and Kollicoat® MAE100P films. The film's properties, including water diffusion coefficient, mechanical properties, plasticizer loss, swelling behavior, and contact angle, were measured for uncured or cured aqueous dispersion-based or organic solvent-based films. The results indicated that curing decreased water diffusivities in films and increased film's tensile strength. Curing resulted in plasticizer loss from SR30D films but not from MAE100P films due to strong interaction between plasticizer and MAE100P. The surface of organic solvent-based films was more hydrophobic than that of aqueous dispersion-based films. The contact angle of organic solvent-based films was increased after curing possibly because curing decreased roughness of the film surface. Organic solvent-based SR30D films had better mechanical properties than the corresponding aqueous dispersion-based films because of higher degree of polymer-polymer entanglement in the organic solvent-based films. However, contradictory phenomena were observed in MAE100P films possibly due to a "core-shell" structure reserved in the aqueous dispersion-based MAE100P films. In summary, casting methods and curing have significant impact on the film properties due to different film structures, coalescence, or film relaxation, and other concurrent effects including evaporation of residue solvent and plasticizers.
Collapse
|
16
|
Yang Y, Shen L, Yuan F, Fu H, Shan W. Preparation of sustained release capsules by electrostatic dry powder coating, using traditional dip coating as reference. Int J Pharm 2018; 543:345-351. [PMID: 29601974 DOI: 10.1016/j.ijpharm.2018.03.047] [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: 12/13/2017] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 11/16/2022]
Abstract
Lately, a great deal of attention is being paid to capsule coating, since the coat protects active pharmaceutical ingredients (APIs) from damage, as is in the case of tablet and pellet. However, moisture and heat sensitivity of gelatin shells make it challenging to coat capsules using the conventional aqueous coating techniques. In an effort to overcome this challenge, the present study aims to coat capsules using two different coating techniques: electrostatic dry powder coating (EDPC) and dip coating (DC). Both capsule coatings and free films were prepared by these two coating techniques, and the effects of coating formulations and processing conditions on the film quality were investigated. The corresponding drug in vitro release and mechanisms were characterized and compared. The results of dissolution tests demonstrated that the drug release behavior of both EDPC and DC coated capsules could be optimized to a sustained release of 24 h, following the Fick's diffusion law. The results of this study suggest that EDPC method is better than DC method for coating capsules, with respect to the higher production efficiency and better stability, indicating that this dry coating technology has promised in gelatin capsule coating applications.
Collapse
Affiliation(s)
- Yan Yang
- School of Pharmacy, Zhejiang University of Technology, Hangzhou, China
| | - Lian Shen
- School of Pharmacy, Zhejiang University of Technology, Hangzhou, China
| | - Feng Yuan
- School of Pharmacy, Zhejiang University of Technology, Hangzhou, China
| | - Hui Fu
- School of Pharmacy, Zhejiang University of Technology, Hangzhou, China
| | - Weiguang Shan
- School of Pharmacy, Zhejiang University of Technology, Hangzhou, China.
| |
Collapse
|
17
|
Cheng L, Gai X, Wen H, Liu D, Tang X, Wang Y, Wang T, Pan W, Yang X. Aqueous Polymer Dispersion Coating Used for Osmotic Pump Tablets: Membrane Property Investigation and IVIVC Evaluation. AAPS PharmSciTech 2018; 19:242-250. [PMID: 28695327 DOI: 10.1208/s12249-017-0837-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/14/2017] [Indexed: 11/30/2022] Open
Abstract
The objective of this study was to investigate the fundamental properties of propranolol hydrochloride osmotic pump tablets coated by aqueous polymer dispersion, simultaneously exploring the in vitro and in vivo correlation of the tablet. The physicochemical properties and parameters of aqueous polymer dispersion membranes (SEM, water uptake, and water vapor transmission coefficient) were investigated. In addition, the release behavior and the in vitro release and in vivo absorption profiles of the tablets coated by aqueous polymer dispersion were investigated by comparing with propranolol hydrochloride osmotic pump tablets coated by an organic solvent. Results showed that the similarity factor (f 2) between cellulose acetate-coated tablet and Eudragit-coated tablet was 78.1, and f 2 between cellulose acetate-coated tablet and Kollicoat-coated tablet was 77.6. The linear IVIVC of Eudragit-coated and Kollicoat-coated osmotic pump tablets was determined, which confirmed excellent correlation between the absorption in vivo and the drug release in vitro. Consequently, the membrane coated by aqueous polymer dispersion or organic solvent has similar in vitro release rates of controlled release. Also, compared with organic solvent coating, aqueous polymer dispersion has numerous advantages, such as reduced toxicity and no environmental damage. Therefore, the aqueous polymer dispersion technology has enormous potential as a replacement of organic solvent coating.
Collapse
|
18
|
Howick K, Alam R, Chruscicka B, Kandil D, Fitzpatrick D, Ryan AM, Cryan JF, Schellekens H, Griffin BT. Sustained-release multiparticulates for oral delivery of a novel peptidic ghrelin agonist: Formulation design and in vitro characterization. Int J Pharm 2017; 536:63-72. [PMID: 29175643 DOI: 10.1016/j.ijpharm.2017.11.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/29/2017] [Accepted: 11/22/2017] [Indexed: 02/01/2023]
Abstract
There is an impetus to provide appropriate sustained release oral delivery vehicles to protect biofunctional peptide loads from gastric degradation in vivo. This study describes the generation of a high load capacity pellet formulation for sustained release of a freely water-soluble dairy-derived hydrolysate, FHI-2571. The activity of this novel peptidic ghrelin receptor agonist is reported using in vitro calcium mobilization assays. Conventional extrusion spheronization was then used to prepare peptide-loaded pellets which were subsequently coated with ethylcellulose (EC) film coats using a fluid bed coating system in bottom spray (Wurster) mode. Aqueous-based EC coating dispersions produced mechanically brittle coats which fractured due to osmotic pressure build-up within pellets in simulated media. In contrast, an ethanolic-based EC coating solution provided robust, near zero-order release in both USP Type 1 and Type 4 dissolution studies. Interestingly, the functionality of aqueous-based EC film coats was restored by first layering pellets with a methacrylic acid copolymer (MA) subcoat, thereby hindering pellet core swelling in acidic media. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) was utilised as a complementary technique to confirm the results seen in USP dissolution studies. Retention of activity of the ghrelinergic peptide hydrolysate in the final encapsulated product was confirmed as being greater than 80%. The described pellet formulation is amenable to oral dosing in small animal studies in order to assess in vivo efficacy of the whey-derived ghrelinergic hydrolysate. In more general terms, it is also suitable as a delivery vehicle for peptide-based bioactives to special population groups e.g paediatric and geriatric.
Collapse
Affiliation(s)
- Ken Howick
- School of Pharmacy, University College Cork, Cork, Ireland; Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland; Food for Health Ireland, University College Cork, Cork, Ireland
| | - Ryan Alam
- School of Pharmacy, University College Cork, Cork, Ireland
| | - Barbara Chruscicka
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Dalia Kandil
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland; Food for Health Ireland, University College Cork, Cork, Ireland
| | - Dara Fitzpatrick
- Department of Chemistry, Analytical and Biological Chemistry Research Facility (ABCRF), University College Cork, Cork, Ireland
| | - Aoife M Ryan
- Food for Health Ireland, University College Cork, Cork, Ireland; Department of Food & Nutritional Sciences, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Harriët Schellekens
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland; Food for Health Ireland, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Brendan T Griffin
- School of Pharmacy, University College Cork, Cork, Ireland; Food for Health Ireland, University College Cork, Cork, Ireland.
| |
Collapse
|
19
|
Kazlauske J, Cafaro MM, Caccavo D, Marucci M, Lamberti G, Barba AA, Larsson A. Determination of the release mechanism of Theophylline from pellets coated with Surelease ®-A water dispersion of ethyl cellulose. Int J Pharm 2017; 528:345-353. [PMID: 28583332 DOI: 10.1016/j.ijpharm.2017.05.073] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/11/2017] [Accepted: 05/31/2017] [Indexed: 11/16/2022]
Abstract
The aim of this study was to investigate the water transport over free standing films based on the aqueous ethyl cellulose (EC) coating Surelease® and the drug (Theophylline) release mechanism from coated pellets. It was found that the main drug release rate from pellets was controlled by a diffusion mechanism. However, the drug release rate was altered by addition of sodium chloride to the external release medium. A decrease in the drug release rate when sodium chloride is added to the release medium has traditionally been used to indicate an osmotic drug release mechanism. However, our findings that the release rate decreased by sodium chloride addition could be explained by sodium chloride diffusing through the coating layer into the inner parts of the pellets, decreasing the solubility of Theophylline. This gave a reduced drug concentration gradient over the coating layer and thus a slower release rate. Furthermore, this study shows, as expected, that the transport of water through Surelease® films into the pellets was faster than the transport out of Theophylline (approx. seven times), which was the reason why the pellets were swelling during the release. It was also shown that the drug release rate, determined for both whole dose release and for single pellets, decreased with increasing thickness (from 16 to 51μm) of the coating layer controlling the drug release rate.
Collapse
Affiliation(s)
- Jurgita Kazlauske
- Pharmaceutical Technology, Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden; SuMo BIOMATERIALS, A VINNOVA VINN Excellence Center at Chalmers University of Technology, Gothenburg 412 96, Sweden
| | | | - Diego Caccavo
- Department of Industrial Engineering, University of Salerno, Fisciano, SA 84084, Italy
| | - Mariagrazia Marucci
- SuMo BIOMATERIALS, A VINNOVA VINN Excellence Center at Chalmers University of Technology, Gothenburg 412 96, Sweden; AstraZeneca R&D Gothenburg, 431 83 Mölndal, Sweden
| | - Gaetano Lamberti
- Department of Industrial Engineering, University of Salerno, Fisciano, SA 84084, Italy
| | - Anna Angela Barba
- Department of Pharmacy, University of Salerno, Fisciano, SA 84084, Italy
| | - Anette Larsson
- Pharmaceutical Technology, Applied Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden; SuMo BIOMATERIALS, A VINNOVA VINN Excellence Center at Chalmers University of Technology, Gothenburg 412 96, Sweden.
| |
Collapse
|
20
|
Jiao X, Li Y, Li F, Sun R, Wang W, Wen Y, Song Y, Zhang X. Voltage-Responsive Controlled Release Film with Cargo Release Self-Monitoring Property Based on Hydrophobicity Switching. ACS APPLIED MATERIALS & INTERFACES 2017; 9:10992-10999. [PMID: 28266208 DOI: 10.1021/acsami.6b16325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Herein, voltage-responsive controlled release film was constructed by grafting ferrocene on the mesoporous inverse opal photonic crystal (mIOPC). The film achieved free-blockage controlled release and realized the monitoring of cargo release without external indicator. Free-blockage was attributed to the voltage switchable nanovalves which undergo hydrophobic-to-hydrophilic transition when applying voltage. Monitoring of cargo release was attributed to the optical property of mIOPC, the bandgap of mIOPC had a red shift when the solution invaded in. The film was hydrophobic enough to stop solution intrusion. Once the voltage was applied, the film became hydrophilic, leading to invasion of the solution. As a result, the cargos were released and the bandgap of mIOPC was red-shifted. Therefore, in this paper both a free-blockage controlled release film and a release sensing system was prepared. The study provides new insights into highly effective controlled release and release sensing without indicator.
Collapse
Affiliation(s)
- Xiangyu Jiao
- Research Center for Bioengineering & Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Yanan Li
- Key Laboratory of Green Printing, Institute of Chemistry Chinese Academy of Sciences (ICCAS), Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS) , Beijing 100190, P. R. China
| | - Fengyu Li
- Key Laboratory of Green Printing, Institute of Chemistry Chinese Academy of Sciences (ICCAS), Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS) , Beijing 100190, P. R. China
| | - Ruijuan Sun
- Research Center for Bioengineering & Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Wenqian Wang
- Research Center for Bioengineering & Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Yongqiang Wen
- Research Center for Bioengineering & Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Yanlin Song
- Key Laboratory of Green Printing, Institute of Chemistry Chinese Academy of Sciences (ICCAS), Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS) , Beijing 100190, P. R. China
| | - Xueji Zhang
- Research Center for Bioengineering & Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing , Beijing 100083, China
| |
Collapse
|
21
|
The importance of the molecular weight of ethyl cellulose on the properties of aqueous-based controlled release coatings. Int J Pharm 2017; 519:157-164. [PMID: 27979762 DOI: 10.1016/j.ijpharm.2016.12.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/09/2016] [Accepted: 12/10/2016] [Indexed: 01/12/2023]
Abstract
Previous investigations of aqueous based ethyl cellulose (EC) latex dispersions have mainly focused on the commercially available viscosity grade 20cps. In this study, dispersions of EC with varying viscosity grades (which correspond to molecular weights), ranging from 4 to 100 cps, were produced and characterised. The dispersions showed particle sizes around 200nm and highly negative ζ-potentials (approx. -100mV), which indicated stable dispersions as confirmed by sedimentation studies. The different latexes were used to produce free-standing film coatings. We hypothesised that the different viscosity grades of EC would result in different properties of the films. We found that an increase in viscosity grade (and higher molecular weight) resulted in lower coalescence between the particles during film formation and thus to higher water permeability than in film coatings of lower molecular weight. After exposure to water the EC 4cps and 20cps film coatings had a more porous structure in the side facing the air during production and drying after immersion in water. Molecular weight is therefore a factor that should be considered when producing pharmaceutical coatings for controlled release.
Collapse
|
22
|
Xue C, Song X, Liu M, Ai F, Liu M, Shang Q, Shi X, Li F, He X, Xie L, Chen T, Xin H, Wang X. A highly efficient, low-toxic, wide-spectrum antibacterial coating designed for 3D printed implants with tailorable release properties. J Mater Chem B 2017; 5:4128-4136. [DOI: 10.1039/c7tb00478h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A broad spectrum antibacterial coatings with tailorable release properties were developed for 3D printed implants.
Collapse
|
23
|
Christian P, Ehmann HMA, Werzer O, Coclite AM. Wrinkle formation in a polymeric drug coating deposited via initiated chemical vapor deposition. SOFT MATTER 2016; 12:9501-9508. [PMID: 27841419 PMCID: PMC5315011 DOI: 10.1039/c6sm01919f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
Polymer encapsulation of drugs is conventionally used as a strategy for controlled delivery and enhanced stability. In this work, a novel encapsulation approach is demonstrated, in which the organic molecule clotrimazole is enclosed into wrinkles of defined sizes. Having defined wrinkles at the drug/encapsulant interface, the contact between the encapsulating polymer and the drug can be improved. In addition, this can also allow for some control on the drug delivery as the available surface area changes with the wrinkle size. For this purpose, thin films of clotrimazole were deposited onto silica substrates and were then encapsulated by crosslinked poly(2-hydroxyethyl methacrylate) (pHEMA) via initiated chemical vapor deposition (iCVD). The thickness and the solid state (crystalline or amorphous) of the clotrimazole layer were varied so that the conditions under which surface wrinkles emerge can be determined. A (critical) clotrimazole thickness of 76.6 nm was found necessary to induce wrinkles, whereby the wrinkle size is directly proportional to the thickness of the amorphous clotrimazole. When the pHEMA was deposited on top of crystalline clotrimazole instead, wrinkling was absent. The wrinkling effect can be understood in terms of elastic mismatch between the relatively rigid pHEMA film and the drug layer. In the case of amorphous clotrimazole, the relatively soft drug layer causes a large mismatch resulting in a sufficient driving force for wrinkle formation. Instead, the increased elastic modulus of crystalline clotrimazole reduces the elastic mismatch between drug and polymer, so that wrinkles do not form.
Collapse
Affiliation(s)
- Paul Christian
- Institute of Solid State Physics, NAWI Graz, Graz University of Technology, 8010 Graz, Austria.
| | - Heike M A Ehmann
- Institute of Pharmaceutical Science, Department of Pharmaceutical Technology, University of Graz, 8010 Graz, Austria and BioTechMed, Graz, Austria
| | - Oliver Werzer
- Institute of Pharmaceutical Science, Department of Pharmaceutical Technology, University of Graz, 8010 Graz, Austria and BioTechMed, Graz, Austria
| | - Anna Maria Coclite
- Institute of Solid State Physics, NAWI Graz, Graz University of Technology, 8010 Graz, Austria. and BioTechMed, Graz, Austria
| |
Collapse
|
24
|
Importance of air bubbles in the core of coated pellets: Synchrotron X-ray microtomography allows for new insights. J Control Release 2016; 237:125-37. [PMID: 27374626 DOI: 10.1016/j.jconrel.2016.06.041] [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] [Received: 04/21/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 12/28/2022]
Abstract
High-resolution X-ray microtomography was used to get deeper insight into the underlying mass transport mechanisms controlling drug release from coated pellets. Sugar starter cores were layered with propranolol HCl and subsequently coated with Kollicoat SR, plasticized with 10% TEC. Importantly, synchrotron X-ray computed microtomography (SR-μCT) allowed direct, non-invasive monitoring of crack formation in the film coatings upon exposure to the release medium. Propranolol HCl, as well as very small sugar particles from the pellets' core, were expulsed through these cracks into the surrounding bulk fluid. Interestingly, SR-μCT also revealed the existence of numerous tiny, air-filled pores (varying in size and shape) in the pellet cores before exposure to the release medium. Upon water penetration into the system, the contents of the pellet cores became semi-solid/liquid. Consequently, the air-pockets became mobile and fused together. They steadily increased in size (and decreased in number). Importantly, "big" air bubbles were often located in close vicinity of a crack within the film coating. Thus, they play a potentially crucial role for the control of drug release from coated pellets.
Collapse
|
25
|
Wu L, Yin X, Guo Z, Tong Y, Feng J, York P, Xiao T, Chen M, Gu J, Zhang J. Hydration induced material transfer in membranes of osmotic pump tablets measured by synchrotron radiation based FTIR. Eur J Pharm Sci 2016; 84:132-8. [DOI: 10.1016/j.ejps.2016.01.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 12/31/2015] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
|
26
|
Melegari C, Bertoni S, Genovesi A, Hughes K, Rajabi-Siahboomi AR, Passerini N, Albertini B. Ethylcellulose film coating of guaifenesin-loaded pellets: A comprehensive evaluation of the manufacturing process to prevent drug migration. Eur J Pharm Biopharm 2015; 100:15-26. [PMID: 26686647 DOI: 10.1016/j.ejpb.2015.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/05/2015] [Accepted: 12/02/2015] [Indexed: 11/19/2022]
Abstract
The aim of the research was to investigate the complete process of pellet production in a Wurster fluidized bed coater in order to determine the main factors affecting the migration phenomenon of a soluble API through the ethycellulose film coating (Surelease®) and hence the long-term stability of the controlled release pellets. Guaifenesin (GFN), as BCS class I model drug, was layered on sugar spheres using a binder-polymer solution containing the dissolved GFN. The drug loaded pellets were then coated with Surelease®. The influence of drug loading (4.5-20.0% w/w), curing conditions (40-60°C and dynamic-static equipment), coating level (12-20% theoretical weight gain) and composition of the binder-layering solution (hypromellose versus Na alginate) on process efficiency (RSDW%), GFN content uniformity (RSDC%), GFN solid state (DSC and XRD) and pellet release profiles was evaluated. The effectiveness of the Surelease film was strongly affected by the ability of GFN to cross the coating layer and to recrystallize on the pellet surface. Results indicated that this behaviour was dependent on the polymer used in the binder-layering solution. Using hypromellose as polymer, GFN recrystallized on the coated pellet surface at both drug loadings. The curing step was necessary to stabilize the film effectiveness at the higher drug loading. Increasing the coating level delayed but did not prevent the GFN diffusion. Replacing hypromellose with Na alginate, reduced the migration of GFN through the film to a negligible amount even after six months of storage and the curing step was not necessary to achieve stable controlled release profiles over storage.
Collapse
Affiliation(s)
- Cecilia Melegari
- Department of Pharmacy and BioTechnology, University of Bologna, Via S. Donato 19/2, 40127 Bologna, Italy
| | - Serena Bertoni
- Department of Pharmacy and BioTechnology, University of Bologna, Via S. Donato 19/2, 40127 Bologna, Italy
| | | | - Kevin Hughes
- Colorcon Ltd, Victory Way, Dartford ME10 5JJ, UK
| | | | - Nadia Passerini
- Department of Pharmacy and BioTechnology, University of Bologna, Via S. Donato 19/2, 40127 Bologna, Italy
| | - Beatrice Albertini
- Department of Pharmacy and BioTechnology, University of Bologna, Via S. Donato 19/2, 40127 Bologna, Italy.
| |
Collapse
|
27
|
Impact of the curing parameters on drug release from Eudragit RS and RL 30D coated pellets: Design of experiments. J Drug Deliv Sci Technol 2015. [DOI: 10.1016/j.jddst.2015.09.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
28
|
Huang XN, Du XY, Xing JF, Ge ZQ. Catalase-only nanoparticles prepared by shear alone: Characteristics, activity and stability evaluation. Int J Biol Macromol 2015; 90:81-8. [PMID: 26318217 DOI: 10.1016/j.ijbiomac.2015.08.056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/24/2015] [Indexed: 12/21/2022]
Abstract
Catalase is a promising therapeutic enzyme; however, it carries risks of inactivation and rapid degradation when it is used in practical bioprocess, such as delivery in vivo. To overcome the issue, we made catalase-only nanoparticles using shear stress alone at a moderate shear rate of 217s(-1) in a coaxial cylinder flow cell. Properties of nanoparticles, including particle size, polydispersity index and zeta potential, were characterized. The conformational changes of pre- and post-sheared catalase were determined using spectroscopy techniques. The results indicated that the conformational changes of catalase and reduction in α-helical content caused by shear alone were less significant than that by desolvation method. Catalase-only nanoparticles prepared by single shear retained over 90% of its initial activity when compared with the native catalase. Catalase nanoparticles lost only 20% of the activity when stored in phosphate buffer solution for 72h at 4°C, whereas native catalase lost 53% under the same condition. Especially, the activity of nanogranulated catalase was decreased only slightly in the simulated intestinal fluid containing α-chymotrypsin during 4h incubation at 37°C, implying that the catalase nanoparticle was more resistant to the degradation of proteases than native catalase molecules. Overall, catalase-only nanoparticles offered a great potential to stabilize enzymes for various pharmaceutical applications.
Collapse
Affiliation(s)
- Xiao-Nan Huang
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Education Ministry Key Laboratory of Systems Bioengineering, Tianjin 300072, PR China
| | - Xin-Ying Du
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Education Ministry Key Laboratory of Systems Bioengineering, Tianjin 300072, PR China
| | - Jin-Feng Xing
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Education Ministry Key Laboratory of Systems Bioengineering, Tianjin 300072, PR China
| | - Zhi-Qiang Ge
- Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Education Ministry Key Laboratory of Systems Bioengineering, Tianjin 300072, PR China.
| |
Collapse
|
29
|
Rongthong T, Sungthongjeen S, Siepmann F, Siepmann J, Pongjanyakul T. Quaternary polymethacrylate–magnesium aluminum silicate films: Water uptake kinetics and film permeability. Int J Pharm 2015; 490:165-72. [DOI: 10.1016/j.ijpharm.2015.05.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/21/2015] [Accepted: 05/17/2015] [Indexed: 11/17/2022]
|
30
|
How to easily provide zero order release of freely soluble drugs from coated pellets. Int J Pharm 2015; 478:31-38. [DOI: 10.1016/j.ijpharm.2014.10.071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 10/28/2014] [Accepted: 10/31/2014] [Indexed: 11/21/2022]
|
31
|
Cilurzo F, Selmin F, Gennari CGM, Montanari L, Minghetti P. Application of methyl methacrylate copolymers to the development of transdermal or loco-regional drug delivery systems. Expert Opin Drug Deliv 2014; 11:1033-45. [DOI: 10.1517/17425247.2014.912630] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|