INVITRO EVALUATION AND OPTIMIZATION OF CONTROLLED RELEASE FLOATING DRUG DELIVERY SYSTEM OF METFORMIN HYDROCHLORIDE

The floating microspheres have been utilized to obtain prolonged and uniform release in the stomachfor development of a once daily formulation. The major advantage of the preparation technique includesshort processing time, the lack of exposure of the ingredients to high temperature, and highencapsulation efficiencies. In the present study, preparation of metformin hydrochloride floatingmicrospheres, evaluation of Floating Drug Delivery System (FDDS) in vitro, prediction of the release,and optimization of floatation and drug release pattern to match target release profile was investigated.Floating microspheres were prepared by non-aqueous emulsification solvent evaporation techniqueusing Ethylcellulose as the rate controlling polymer and 250 mg of metformin hydrochloride per batchand its in vitro performance was evaluated by the usual pharmacopoeial and other tests such as drugpolymercompatibility (FTIR scan), yield (%), particle size analysis, drug entrapment efficiency, surfacetopography, and in vitro floatation and release studies. Results showed that the mixing ratio ofcomponents in the organic phase affected the size, size distribution (250-1000 μm), drug content(61 – 134% of theoretical load), yield (58 – 87%) and drug release of microspheres (47 – 87% after 8 h),floating time ( 8 hr) and the best results were obtained at the ratio of drug: polymer: solvent(250:750:12 and 250:146.45:9 [mg: mg: ml]), when both the batches were mixed in equal proportions.In most cases good in vitro floating behavior was observed and a broad variety of drug release patterncould be achieved by variation of the polymer and solvent ratio, which was optimized to match targetrelease profile. The developed floating microspheres of metformin hydrochloride may be used in clinicfor prolonged drug release in stomach for at least 8 hrs, thereby improving the bioavailability and patient compliance.