Evaluation of Ethyl Cellulose as Microencapsulating Agent for Controlled Release of Glimepiride

Abstract

The objective of the study is to evaluate ethyl cellulose, a plastic insoluble polymer for its application as microencapsulating agent for controlled release of glimepiride. Ethyl cellulose coated microcapsules of glimepiride were prepared by an industrially feasible emulsification-solvent evaporation method and were evaluated for controlled release. These microcapsules were spherical, discrete, free flowing and multinucleate monolithic type. Microencapsulation efficiency was in the range 68-89 %. Glimepiride release from the microcapsules was slow over 24 h and depended on core:coat ratio, wall thickness and size of the microcapsules. Drug release from the microcapsules was by non-fickian (anamolous) diffusion mechanism. Good linear relationship was observed between wall thickness of the microcapsules and release rate.