23PREPARATION AND EVALUATION OF FLOATING MICROSPHERES OF REPAGLINIDEThe present study involves preparation and evaluation of floating hollow microspheres of Repaglinide for improving the drug bioavailability by prolongation of gastric residence time. Repaglinide (an oral hypoglycemic agent) is a lipophillic drug hence it is absorbed rapidly from the stomach, quickly eliminated and having short half-life. So it is suitable to formulate gastro-retentive floating drug delivery system. Floating microspheres of Repaglinide were prepared by Emulsion solvent diffusion technique using Ethyl cellulose, Eudragit RL PO and Eudragit RS PO as retarding polymers. The prepared formulations were evaluated for micrometric properties, particle size, percentage yield, % entrapment efficiency, % drug loading, in vitro buoyancy drug polymer compatibility (FTIR study), scanning electron microscopy, in vitro drug release studies and drug release kinetics was evaluated using the linear regression method. The microspheres had smooth surfaces, with freeflowing and good-packing properties. FTIR study indicated that there was no interaction between the drug and polymers. Scanning electron microscopy confirmed their hollow structure with smooth surface. The mean particle size, practical yield (82.32%), entrapment efficiency (77.01±0.216%) were increased and the drug release rate decreased at higher polymer concentration. The prepared microspheres exhibited prolonged drug release and remained buoy ant for more than 12 h. In vitro release studies demonstrated non-fickian diffusion of drug from microspheresrirampharma@gmail.comResearch312013Floating hollow microspheres,Repaglinide,Gastro-retentive drug delivery system,Ethyl cellulose,EudragitSushma R,Sriram NDepartment of Pharmaceutics, Smt. Sarojini Ramulamma College of Pharmacy, Mahabub Nagar, Andhra Pradesh, India,Department of Pharmaceutics, Smt. Sarojini Ramulamma College of Pharmacy, Mahabub Nagar, Andhra Pradesh, India