Indomethacin loaded chitosan microspheres. Correlation between the erosion process and release kinetics

Abstract

The preparation of chitosan microspheres covalently linked with citric acid and loaded with indomethacin is described. The release kinetics correlated with the concentration of chitosan in the microsphere preparative mixture and the pH of the release medium. Deviations from Fickian to zero order kinetics were observed at higher concentrations of chitosan and at pH 7·4. The variations induced by these parameters on drug diffusion and solubility in the matrix undergoing erosion were analysed.

Key Words:

• Chitosan
• indomethacin
• crosslinking
• erosion
• release kinetics
• microspheres