Mechanism of Ibuprofen release from chitosan granules

Abstract

Attempts have been made to formulate controlled release drug dosage forms using chitosan as a release controlling polymer. Granules of combination of chitosan, hydroxylpropyl cellulose, lactose, starch and Ibuprofen were prepared by wet granulation method using 1.0% lactic acid solution. The granules were physico-chemically characterized in terms of density, porosity, angle of repose, carr’s index and housner ratio and was found to be free flowing with good compressibility. FTIR spectroscopy was used and confirmed that there is no interaction between the drug and the added polymers. In vitro release of Ibuprofen, in phosphate buffer at pH 7.4, showed a steady and slow increase in the percentage of drug released over 24 hours as the percentage of chitosan was increased in the formulations compared to that from commercial tablets which released over 80.0% of their content in only two hours. The kinetic analysis using different mathematical models of the data revealed that the release kinetics of the drug form these formulations is somewhere between diffusion controlled, Fickian (anomalous) and non-Fickian which refers to a combination of diffusion and erosion controlled release. Thus, the high correlation coefficient of the data of drug release from most granules when zero order kinetics was applied revealed that there is a constant drug release with time for 24 hours.