Polymeryounis
Nov 13, 2016
Research Papers / Modeling And Optimization Of Swelling, Drug Loading And Release From Natural Polymer Hydrogels [2]
Abstract
The present work deals with synthesis of composite natural polymer hydrogels (Sodium alginate-Chitosan- Gum Arabic) as beads. The beads are formulated with different polymer proportions according to an experimental central composite design using RSM methodology. The degree of swelling of the polymer beads in acidic and neutral mediums was investigated, analyzed, modeled and optimized statistically. A typical drug was loaded in the optimized polymer formulations. The loading capacity and in vitro release profiles were estimated. The shape and morphological analysis for the beads before and after drug releasing have been investigated using a Scanning Electron Microscope (SEM). The results obtained confirmed that Gum Arabic content is the only significant parameter in the swelling process regardless the pH of the swelling media. The swelling indices of the beads are higher in acidic (pH 3.9) compare to that in (pH 7.1), indicating a pH-sensitive swelling behavior. An optimum response surface analysis results for swelling indices of 504.98 % and 207.97 % are obtained in acidic and neutral medium respectively. The in vitro drug release in the acidic medium within the initial two hours seemed to be minor ( 12.2-17.8 %), then increases depending on the loading amount of the drug, reaching an equilibrium after 12 hours where the major quantity of the drug (86.8-91.6 % ) is released from the polymer beads. The SEM analysis of the polymer beads before and after drug release confirms the big difference in beads morphology. The compacted structure of the beads before drug release shows morphological changes and the beads lost their shape due to erosion and swelling activities after releasing of the drug.
Abstract
The present work deals with synthesis of composite natural polymer hydrogels (Sodium alginate-Chitosan- Gum Arabic) as beads. The beads are formulated with different polymer proportions according to an experimental central composite design using RSM methodology. The degree of swelling of the polymer beads in acidic and neutral mediums was investigated, analyzed, modeled and optimized statistically. A typical drug was loaded in the optimized polymer formulations. The loading capacity and in vitro release profiles were estimated. The shape and morphological analysis for the beads before and after drug releasing have been investigated using a Scanning Electron Microscope (SEM). The results obtained confirmed that Gum Arabic content is the only significant parameter in the swelling process regardless the pH of the swelling media. The swelling indices of the beads are higher in acidic (pH 3.9) compare to that in (pH 7.1), indicating a pH-sensitive swelling behavior. An optimum response surface analysis results for swelling indices of 504.98 % and 207.97 % are obtained in acidic and neutral medium respectively. The in vitro drug release in the acidic medium within the initial two hours seemed to be minor ( 12.2-17.8 %), then increases depending on the loading amount of the drug, reaching an equilibrium after 12 hours where the major quantity of the drug (86.8-91.6 % ) is released from the polymer beads. The SEM analysis of the polymer beads before and after drug release confirms the big difference in beads morphology. The compacted structure of the beads before drug release shows morphological changes and the beads lost their shape due to erosion and swelling activities after releasing of the drug.
