FORMULATION AND EVALUATION OF METFORMIN HYDROCHLORIDE MICROPARTICLES BY EMULSION SOLVENT EVAPORATION TECHNIQUE

Abstract

Metformin HCl-loaded microparticles of ethyl cellulose were prepared by the emulsion solvent evaporation technique. The aim of this work was to investigate the influence of process variation in polymer type via viscosity grades of ethyl cellulose E1and E10 and drug to polymer ratio on the micromeritic properties. Microparticles evaluated for various characteristic properties such as encapsulation efficiency, particle size & size distribution, surface morphology and drug release pattern. The optimized formulation parameters were used to prepare porous, spherical micro particles (67 μm to 127 μm) with high encapsulation efficiency (93 to 97%). Drug release over a period of 12 hrs ranged from 85.7 % to 98.3 %. Microspheres were more spherical in shape in their manufacture with ethyl cellulose E10 and higher ratio of both polymers. Thus, in the case of ethyl cellulose, the viscosity and ratio of the polymer in dispersion medium were found to be the controlling factors of drug release. Key words: Metformin, Ethyl cellulose, micro particles, sustained release, encapsulation efficiency.