Preparation and In-vitro Characterization of Floating Microspheres of Nateglinide

Gastric residence time of oral controlled release system such as microspheres is increase by different techniques such as floating and mucoadhesive system. The objective of present investigation was to formulate floating microspheres of Nateglinide in order to increase gastric residence time, increased bioavailability and to reduce dose frequency of drug molecule. Novel o/w emulsion solvent diffusion technique was used to prepare microspheres of Nateglinide by using various polymers such as HPMC, Ethyl cellulose and Eudragit S100. Entrapment efficiency of drug was upto 69%. Eudragit S100 based microspheres which were found to be hollow cavity, spherical and porous nature from the results of scanning electron microscopy. Micromeritic profile of prepared microballoons was found satisfactory. From the results of FTIR spectroscopy it was reveal that there is no drugpolymer interaction. Eudragit S100 based microspheres shows good in vitro buoyancy and sustained release profile for longer period of time > 14 hours. The formulation had followed first order kinetics as its release mechanism was diffusion controlled.