The objective of the present work was to formulate floating hollow microspheres of Rosiglitazone Maleate (RSM), which is soluble and shows better absorption in gastric pH. Microspheres were prepared by modified Quasi-emulsion diffusion technique using ethyl cellulose, eudragit S100, polyethylene oxide and Hydroxyproply methyl cellulose (HPMC K15M) as polymers. The formulations were evaluated for micromeritic properties, in vitro, in vivo buoyancy, % yield, entrapment efficiency, in vitro and in vivo release studies. They were characterized by FT-IR and DSC. FT-IR and DSC studies indicated that there was no interaction between the drug and polymers. SEM photographs showed the outer surface of microspheres was smooth and dense where as internal surface was porous which helped to prolong floating to increase residence time in stomach. The results showed that floating microspheres could be successfully prepared with better yield (more than 54.5 ±1.2 %), high encapsulation efficiency (53±2.2 %) and narrow size distribution (223±2.7-446±5.2 μm). All the formulations floated for more than 8 h. Results showed larger the particle size, longer was the floating time. In vivo evaluation in albino rabbit confirmed floating capability microspheres for more than 8 h. In vitro drug release studies showed controlled release of rosiglitazone maleate for over 12 h. The release behaviour best fitted mostly in peppas and zero order equations. In vivo evaluation of blood glucose levels in albino rats showed that floating microspheres of rosiglitazone maleate had better glycemic control than conventional dosage form. From the results it can be concluded that gastric floating hollow microspheres can be successfully used for the delivery of rosiglitazone maleate to control blood glucose level.
