Formulation and Evaluation of Effervescent Floating Tablet of Famotidine

Famotidine has been the most widely used drug for the treatment of peptic ulcer for many decades. The present investigation concerns the development and evaluation of floating tablets of famotidine which, after oral administration, are designed to prolong the gastric residence time, increase drug bioavailability and target the gastric ulcer. A floating drug delivery system (FDDS) was developed using gas-forming agents, like sodium bicarbonate, citric acid and hydrocolloids, like hydroxypropyl methylcellulose (HPMC) and carbopol 934P. The prepared tablets were evaluated in terms of their precompression parameters, physical characteristics, in vitro release, buoyancy, buoyancy lag-time and swelling index. The formulations were optimized for the different viscosity grades of HPMC, carbopol 934P and its concentrations and combinations. The results of the in vitro release studies showed that the optimized formulation (F12) could sustain drug release (98%) for 24 h and remain buoyant for 24 h. The optimized formulation was subjected to various kinetic release investigations and it was found that the mechanism of drug release was predominantly diffusion with a minor contribution from polymeric relaxation. Optimized formulation (F12) showed no significant change in physical appearance, drug content, total buoyancy time or in vitro dissolution study after storage at 45 °C/75% RH for three months. Finally the tablet formulations found to be economical and may overcome the draw backs associated with the drug during its absorption.