The purpose of this research study was to develop and optimize a controlled- release floating tablet of highly water soluble drug Nizatidine in an effort to increase its gastric retention time in the stomach. The tablets were prepared by direct compression method and Hydroxypropylmethylcellulose (HPMC) of different viscosity grades, Carboxymethyl cellulose Sodium (NaCMC) were incorporated as retarding polymers. Sodium bicarbonate was incorporated as effervescent agent. Formulations were evaluated for weight variation, thickness, hardness, percentage swelling, friability, and in vitro drug release, and floating lag time, total duration of floating, dissolution efficacy and in vivo Mean Residence Time (MRT) in the stomach. The formulation F6 with HPMC K 4M exhibited floating lag time of less than 1min and floating time of more than 12 hrs. The drug release of the optimized formulation followed Higuchi kinetic model (R2=0.9832) and the mechanism of drug release was found to be super case II according to Krosmeyer-Peppas (n value is 0.60). In vivo nature of tablet was observed at different time intervals with help of radiographic pictures in healthy human volunteers and MRT in the stomach was found to be 320 minutes.
