Design and Characterization of Floating Microspheres of Rabeprazole Sodium for Prolonged Gastric Retention

Floating drug delivery system is one of the novel drug delivery system. Floating drug delivery system have a bulk density less than gastric fluids and so remain buoyant in the stomach without affecting gastric emptying rate for a prolonged period of time. The aim of the present study was to develop floating microspheres of Rabeprazole sodium(RPS), which belong to class of proton pump inhibitor. Floating microspheres of Rabeprazole were prepared by emulsion solvent evaporation method using HPMC K15M and ethyl cellulose as polymer. Six different formulations were developed. The floating microsphere was evaluated for angle of repose, particle size, percentage yield, in vitro buoyancy, incorporation efficiency, drug polymer compatibility (IR study), scanning electron microscopy, drug release and DSC(Differential Scanning colorimetry), X-Ray Diffraction(XRD) of microsphere. Results show that as the concentration of polymer increases it affects the particle size, percentage yield, in vitro buoyancy and drug release of microsphere. Formulations prepared with HPMC K15M exhibited excellent Micromeritic properties, percentage yield, in vitro buoyancy, incorporation efficiency and percentage drug release when compared to ethyl cellulose polymer. Results of our present study suggest that floating microsphere of Rabeprazole sodium can be successfully designed to develop controlled drug delivery which can reduce dosing frequency thus this formulation can be considered as an alternative to conventional dosage forms. Key words: floating drug delivery systems, Rabeprazole sodium (RPS), incorporation efficiency, dosing frequency, DSC(Differential Scanning colorimetry)  X-Ray Diffraction (XRD)