Microencapsulation of Verapamil Hydrochloride: A Novel Approach for Gastric Retention Using Different Polymers

Abstract

The aim of the present investigation was to prepare and evaluate gastroretentive floating microspheres of Verapamil hydrochloride that would retain the drug in stomach and continuously release the drug in controlled manner up to a predetermined time. Floating microspheres were prepared by emulsion solvent evaporation technique. In the present investigation three polymers were used in various concentrations; Methocel K4M, Methocel K15M and Methocel K100M. In vitro performance was evaluated by the usual pharmacopoeial and other tests such as particle size analysis, drug entrapment efficiency, flow properties, in vitro floatability studies, in vivo floatability studies in dog, in vitro drug release studies, stability studies etc. Results showed that the mixing ratio of components in the organic phase affected the size, size distribution, yield, drug content, floating time and drug release of microspheres. In most cases good in vitro floating behavior was observed and a broad variety of drug release pattern could be achieved by variation of the drug, polymer and solvent ratio.