FORMULATION AND IN VITRO EVALUATION OF FLOATING TABLETS OF PSYLLIUM HUSK & TRAGACANTH USING SITAGLIPTIN PHOSPHATE AS A MODEL DRUG

Abstract A novel floating controlled release drug delivery system of Sitagliptin phosphate was formulated in an effort to increase the gastric retention time of the dosage form and thereby increased drug bioavailability. The tablets were prepared by wet granulation method using Psyllium Husk and tragacanth gum as a release retarding polymers and sodium bicarbonate as a gas generating agent. All the designed nine batches of floating tablets were evaluated for physical characteristics viz. weight variation, thickness, content uniformity, hardness, floating capacity, swelling studies. All formulations had floating lag time of less than 1 min and constantly floated for 12 h except F1, F4 and F7 (that dissolved completely in 8 h or less than 8 h). In vitro drug release studies were carried out for 8 h and release mechanism was further evaluated by linear regression analysis, F9 composed of 30% Psyllium Husk, 10% tragacanth gum and 18% sodium bicarbonate sustained the drug release for longer period. The formulations followed first order kinetics, Higuchi drug release kinetics with diffusion as the dominant mechanism of drug release and the release exponent ranged (0.452-0.635) indicating that the drug release from all formulations was by non-Fickian diffusion mechanism. The prepared floating tablets of STP (F9) might be a promising drug delivery system with sustained release action and improved bioavailability.