FORMULATION DESIGN AND EVALUATION OF GASTRORETENTIVE FLOATING DOSAGE FORM OF H2-RECEPTOR ANTAGONIST

The objective of the present investigation is to formulate gastroretentive dosage form of Nizatidine, a H2-receptor antagonist widely prescribed in gastric ulcers, duodenal ulcers. The short biological half-life (1 - 2 hours), maximum absorption in initial part of small intestine, colonic metabolism of Nizatidine favors’ development of gastro retentive floating dosage form. In the present study Nizatidine floating tablets were prepared by effervescence method using sodium bicarbonate as a gas generating agent. The tablets were formulated using direct compression technology by employing semi synthetic polymers like various grades of HPMC such as HPMC K4M, K15M, K100M and natural polymers like xanthan gum and kondagogu gum. drug-excipient compatible studies by FTIR and DSC , The FTIR and DSC study revealed that there is no drug-excipient interaction. The prepared tablets were evaluated for various physicochemical parameters such as flow properties, hardness, weight variation, friability, in vitro buoyancy (floating lag time, total floating time), swelling studies, drug content and in-vitro drug release. The in vitro drug release pattern of Nizatidine floating tablets was fitted to different kinetic models which showed highest regression for zero order kinetics with non fickian diffusion mechanism. Out of all formulations the one prepared with combination of HPMC K4M and K15M was optimized based on desired sustained release time (12hrs) and acceptable floating properties