Preparation and Evaluation of Ethyl Cellulose Coated Microcapsules of Pioglitazone for Controlled Release

Abstract

The objective of the study is to prepare and evaluate ethyl cellulose coated microcapsules of pioglitazone for controlled release. Controlled release formulations are needed for pioglitazone because of its short biological half life and for better control of blood glucose levels to prevent hypoglycemia, to enhance clinical efficacy and patient compliance. Ethyl cellulose microcapsules of pioglitazone were prepared by an industrially feasible emulsification-solvent evaporation method and the microcapsules were evaluated for controlled release. The ethyl cellulose microcapsules prepared are spherical, discrete, free flowing and multi nucleate monolithic type. Microencapsulation efficiency was in the range 96.34-104.30 %. Pioglitazone 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 diffusion mechanism. Good linear relationships were observed between wall thickness of the microcapsules and release rate. Ethyl cellulose was found suitable as a microencapsulating agent for pioglitazone and the ethyl cellulose microcapsules exhibited good controlled release characteristics and were found suitable for once-a-day administration of pioglitazone.