Formulation Optimization of A Floating Extended Release Matrix Tablet of Metformin Hydrochloride

  The purpose of the present study was to develop an optimized gastric floating extended release matrix tablet of Metformin hydrochloride (FERMTs) using a hydrophilic polymer, HPMC K4M, a hydrophobic polymer ethyl cellulose and sodium bicarbonate as buoyancy contributor. The formulation of FERMTs were designed by D-optimal mixture design taking % of HPMC K4M, ethyl cellulose and sodium bicarbonate as formulation variables and prepared by wet granulation method. The FERMTs were then evaluated for hardness, friability, weight variation, content uniformity, in vitro drug release and floating capacity. Finally, the floating lag time (FLT) and cumulative % drug release at 1h, 2h, 6h and 10h were taken as response variables and the FERMT formulation was numerically optimized by D-optimal mixture design using Design-Expert software (version 8.1). The optimized formula showed excellent floating efficiency over 10 h period with FLT of 9.61 mins. The release profile of optimized formula showed much closed similarity with that of USP reference dissolution profile (f2 value= 87.95). Analysis of dissolution data showed that the kinetic of drug release followed Korsemeyer-Peppas and Higuchi model.