In vitro release of salicylic acid through poly(vinyl alcohol-g-itaconic acid) membranes

2007 ◽  
Vol 107 (5) ◽  
pp. 3291-3299 ◽  
Author(s):  
Gülsen Asman ◽  
Oya Şanlı ◽  
Didem Tuncel
2011 ◽  
Vol 68 (7) ◽  
pp. 1905-1919 ◽  
Author(s):  
K. Madhusudana Rao ◽  
B. Mallikarjuna ◽  
K. S. V. Krishna Rao ◽  
M. N. Prabhakar ◽  
K. Chowdoji Rao ◽  
...  

2018 ◽  
Vol 10 (6) ◽  
pp. 309
Author(s):  
Aya M. Dawaba ◽  
Hamdy M. Dawaba ◽  
Amal S. M. Abu El-enin ◽  
Maha K. A. Khalifa

Objective: The objective of this current study is to fabricate ocuserts to control the drug release from chosen bioadhesive polymeric matrixes to enhance patient compliance. Ciprofloxacin HCl (CFX HCl) was selected as a model drug.Methods: Different bioadhesive polymers with different film forming capabilities namely Hydroxy Propyl Methyl Cellulose (HPMC K4M), Poly Vinyl Alcohol (PVA), Sodium Carboxy Methyl Cellulose (Na CMC), Hydroxy Propyl Cellulose (HPC), Sodium Alginate (Na Alg.), pullulan and Xanthan Gum (XG) in different ratios were used in fabricating ocuserts using solvent-casting technique. Propylene Glycol (PG) was used as a plasticizer to facilitate the fabrication process. Characterization tests of the developed ocuserts were performed as well as bioadhesive tests and in vitro release studies of the incorporated drug. The obtained results were analysed using different release kinetic models. Stability of the selected ocuserts was investigated at 40±0.5 °C and 75±5% Relative Humidity (RH) for three months’ storage period. In vivo ocular irritation test was performed to investigate the safety of the formula in rabbits’ eyes as well as to test the release profile and thus to estimate In vitro In vivo correlation.Results: All the prepared ocuserts showed the uniformity of film characterization and bioadhesion strength ranged from 240±66 and 158±52dyne/cm2. Selected formula from the in vitro release study tested for in vivo study showed the slow release of ciprofloxacin drug up to 24 h with no signs of eye irritancy. Results for In vitro In vivo correlation showed an excellent correlation with R2 value of 0.9982.Conclusion: PVA based ocuserts proven to be a promising once-daily, effective and safe ocular delivery system of the drug.


2017 ◽  
Vol 9 (3) ◽  
pp. 37
Author(s):  
Satish C. S.

Objective: The purpose of this study was to ascertain the applicability of degradable materials for fabrication of an insulin release system.Methods: Insulin implants were prepared by using poly (vinyl alcohol) (PVA), gellan and chitosan by solution casting method. The prepared implants were evaluated for swellability, content uniformity, potency and purity of insulin in implants, scanning electron microscopy studies, in vitro release studies, in vitro degradation studies using lysozyme, stability studies and circular dichroism spectroscopy.Results: The swelling degree of the implants was found to be in the range of 1.07-1.56. The diffusion coefficient of water through the implant was found to depend on the calcium chloride (CaCl2) concentration. The diffusion coefficient of insulin through the chitosan-PVA-gellan in the early stages was found to be in the range of 1.99´10-5 cm2/sec to 5.24´10-5 cm2/sec and at later stages in the range of 6.9´10-6 cm2/sec to 1.10´10-5 cm2/sec. The weight of the implants was 48±0.58 mg. The insulin content in the implants was 9.86±0.10 mg. The potency of insulin extracted from the implants was 27.11±0.75 U/mg or 95.12±2.61 % of the control insulin. The in vitro release studies showed that insulin was released completely in a period of 13-19 d depending on the composition of the implant. The increase in CaCl2 retarded the rate of insulin release whereas the increase in PVA content leads to the rapid release of insulin. The device was found to undergo significant weight loss due to enzyme mediated degradation.Conclusion: These studies provide validity for the potential utility of chitosan-PVA-gellan implant systems for the delivery of insulin. The studies also demonstrate that insulin maintained its integrity within the implant system. Implants showed the complete release of insulin in 19 d and the release of insulin from the implants depended on the amount of CaCl2.


Author(s):  
Biswajit Basu ◽  
Kevin Garala ◽  
Thimmasetty J

Within the oral mucosal cavity, the buccal region offers an attractive route of administration for systemic drug delivery. Pimozide patches were prepared using HPMC (15 & 47 cPs), carbopol 934, poly vinyl alcohol, and poly vinyl pyrolidone. FTIR and UV spectroscopic methods revealed that there is no interaction between pimozide and polymers. The patches were evaluated for their thickness uniformity, folding endurance, weight uniformity, content uniformity, swelling behaviour, tensile strength, and surface pH. In vitro release studies of pimozide-loaded patches in phosphate buffer (pH, 6.6) exhibited drug release in the range of 55.32 % to 97.49 % in 60 min. Data of in vitro release from patches were fit in to different equations and kinetic models to explain release kinetics. The models used were zero and first-order equations, Hixon-Crowell, Higuchi and Korsmeyer-Peppas models. In vivo absorption of pimozide from all the patches ranged from 47.96 % to 83.42 % in 60 min in human volunteers. In vivo studies in rabbits showed 85.97% of drug absorption from HPMC-15 cPs patch in 60 min. Good correlation among in vitro release and in vivo absorption of pimozide was observed


1991 ◽  
Vol 80 (11) ◽  
pp. 1072-1074 ◽  
Author(s):  
Masakazu Kawata ◽  
Tatsuya Suzuki ◽  
Nak-Seo Kim ◽  
Takahiro Ito ◽  
Atsuko Kurita ◽  
...  

2013 ◽  
Vol 709 ◽  
pp. 215-220 ◽  
Author(s):  
Dou Dou Zhang ◽  
Li Xing Dai

A series of poly(vinyl alcohol)/silk fibroin nanofibers loaded with 10 wt.% vanillin were successfully prepared from aqueous solutions via electrospinning. The morphology, weight loss and swelling ability of the nanofibers were characterized. The controlled release characteristics of vanillin in the nanofiber mats were evaluated by in vitro release test. Vanillin-loaded nanofibers had smooth surfaces like drug-free nanofibers, and showed thinner diameter than the latter. The release rate of vanillin in the nanofiber mats decreased with the increment of silk fibroin content, so by regulating the content the drug release could be controlled. Moreover, after treated with ethanol the nanofiber mats showed better stability against disintegration in water and sustained release rate of vanillin than untreated mats.


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