FORMULATION AND EVALUATION OF MICROSPHAERS OF METFORMIN HYDROCHLORIDE

The objective of the present study was to develop sustained release microspheres of Metformin hydrochloride in order to achieve an extended retention in the GIT which may result in enhanced absorption and there by improved bioavailability. The present worker prepared microspheres of Metformin hydrochloride in nine batches using ethyl cellulose (EC) and Poly Vinyl Alcohol (PVA) in different drug polymer ratios taking into account solvent evaporation method. Infrared Spectrophotometric analysis revealed that there was no known chemical/physical interaction between drug & polymer and/or excipients used. The formulations of different batches were subjected to various physicochemical studies such as % yield, particle size, drug entrapment efficiency, in-vitro drug release and stability studies. The results showed that the method was reproducible and easy for the formulation of microspheres. Effect of polymer concentration was also evaluated with respect to their size & drug entrapment parameter studies. The in-vitro release studies indicated that the Metformin hydrochloride loaded microspheres provided sustained drug release over a period of 12 hrs. The optimized batch (B2) showed percentage yield: 57.9, particle size: 200 μm, EE (entrapment efficiency): 60.41% and drug release in 0.1N HCl: 92.853±1.429%. None other than the present worker has reported microsphere formulation with this particular drug using Ethyl cellulose, poly vinyl alcohol and dichloromethane. Therefore, the research, in reference, comprised of quite novel aspects of investigations.