Formulation and Evaluation of Floating Nateglinide Tablets Using Factorial Design

Nateglinide is a novel, highly physiologic, glucose regulator recently approved for the treatment of type-2 diabetes mellitus. Nateglinide has a rapid onset and short duration of insulinotropic action that results in reduction of glucose level. The purpose of this study to develop a floating tablet of Nateglinide to enhance its bioavailability and sustained action. In the present study a 32 full factorial design was employed in which 2 factors were evaluated at 3 levels, experimental trials were performed at all possible 9 combinations. The independent variables selected for this study were concentration of Ethyl cellulose (X1) and sodium bicarbonate (X2). % drug release for 30min,1h, 2h,4h,6h, 8h,12h, 16h,24h and floating lag time (FLT) were as dependent variables. The results of factorial design showed that factor X1 and X2 significantly affect the studied dependent variables. The floating tablet formulations were evaluated for Bulk density (gm/cm3), Tapped density(gm/cm3), Hausner ratio(HR), Carr index, Angle of repose, flow property, assay, invitro drug release, hardness, friability,weight variation. The results of in vitro release studies showed that the optimized formulation (F8) could sustain drug release (98.33%) for 24h. Stability of tablets at 400C/75%RH, of optimized formulation was carried for one month and no significant change was observed.