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Drug release mechanisms from composite matrices II. Experimental issues

Abdekhodaie, M. J ; Sharif University of Technology | 2002

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  1. Type of Document: Article
  2. Publisher: Sharif University of Technology , 2002
  3. Abstract:
  4. In this paper, the theoretical issues governing release characteristics of a solute of composite materials are validated experimentally, using composites of cross-linked poly (hydroxyethyl methacrylate) (PHEMA) particles dispersed within ethylene vinyl acetate copolymer (EVAc) matrices, and composites of cross-linked poly (methacrylic acid) (PMAA) particles dispersed within poly (dimethyl siloxane) (PDMS) networks which were prepared. Using theophylline and caffeine as the model drugs, the results of release, permeation and swelling experiments were employed to validate the theoretical issues. In PHEMA-EVAc matrices, due to equilibrium swelling, Fickian diffusional release kinetics was observed. In PMAA-PDMS matrices, which contained 19%wt, 23.7%wt, 28.5%wt, 33.2%wt and 38%wt PMAA, because of osmotic rupturing, pseudo-zero-order release kinetics preceded by a marked burst effect was observed. In all the cases, the experimental results were in good agreement with the theoretical criteria for equilibrium swelling versus osmotic rupturing. For the model predicting the extent of equilibrium swelling, the maximum deviation of the swelling ratio compared to the experimental results for different matrices was only 8.4%
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  7. Source: Scientia Iranica ; Volume 9, Issue 1 , 2002 , Pages 9-18 ; 10263098 (ISSN)
  8. URL: http://scientiairanica.sharif.edu/article_2719.html