| Autor: |
William I. Higuchi, Miyajima Masaharu, Sung Wan Kim, Okano Teruo |
| Rok vydání: |
1987 |
| Předmět: |
|
| Zdroj: |
Journal of Controlled Release. 5:179-186 |
| ISSN: |
0168-3659 |
| DOI: |
10.1016/0168-3659(87)90009-5 |
| Popis: |
In order to develop a new transdermal delivery system providing variable drug delivery rates for antiviral Ara-A (9-β-arabino-furanosyladenine), it was first necessary to develop a method for designing rate-limiting polymeric membranes in transdermal devices having different permeability coefficients for Ara-A. Poly (2-hydroxyethyl methacrylate) (pHEMA) and copolymers of styrene (St) or N -vinylpyrrolidone (VP) with HEMA have been synthesized and the relationship between the hydration of membranes and the diffusion parameters has been investigated. The results of swelling measurements showed that swelling of polymer membranes was affected by the composition of copolymers, in which VP has a strong swelling effect and St has a deswelling effect. It is possible to control swelling properties in a range of approximately 46% to 195% at 37 °C in saline solution. The permeability coefficients of Ara-A in the copolymers showed a significant increase with increasing swelling of the copolymer membranes, and a good correlation between the permeability coefficient and swelling was observed. The observed linear relationship between the reciprocal of the hydration and the diffusion coefficients supports a diffusion mechanism based on the free-volume theory. The results show that the permeability coefficient of AraA through p(HEMA-VP) and p (HEMA-St) could be controlled in the range from 10 −5 to 10 −8 cm/s by changing the copolymer composition following the concept of a hydration-controlled transport process. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
