Studies on the Release of Theophylline from Polyvinylacetate Microspheres

Abstract

Polyvinylacetate microspheres containing theophylline were prepared by emulsification and solvent removal method. The release pattern of theophylline from the microspheres was found to be best explained by diffusion controlled process. The rates of release were found to be influenced by drug-polymer ratios, size of microspheres, concentration of surfactant used for the preparation of microspheres, and pH of the dissolution media.