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.This present study involves Formulation and evaluation of floating microspheres of Metformin Hcl as model drug for prolongation of gastric residence time. The microspheres were prepared by the Non Aqueous solvent diffusion method using polymers hydroxy propylmethyl cellulose and ethyl cellulose. The melting point study was performed by differential scanning calorimetry, compatability studies between the drug and polymer was observed by using the FTIR Analysis.The melting point is determined by DSC. The shape and surface morphology of prepared microspheres was characterized by motic and scanning electron microscopy, respectively. In vitro drug release studies were performed, and drug release kinetics were evaluated using the linear regression method. The prepared microspheres exhibited prolonged drug release (12 hr) and remained buoyant for > 13 hr. The mean particle size increased and the drug release rate decreased at higher polymer concentration. In vitro studies demonstrated super case II transport diffusion from the microspheres. By the observation and of all formulations results we concluded that formulation 9 having the better drug release.
