Abstract:
The present investigation concerned with the development of Hydrodynamically Balanced Tablets of Ranitidine, which after oral administration are designed to prolong the gastric residence time and there by increase drug bioavailability. Preliminary trial batches were prepared and the best combination was selected on the basis of the floating behavior (floating time, total floating lag time). Than Ten batches of tablets were fabricated containing drug, and various grades of polymers HPMC K4M, HPMC K15M, HPMC K100M, HPMC 15cps, HPMC 3cps, and carbopol, along with gas generating agent sodium bicarbonate and calcium carbonate with acidulent adipic acid by using wet granulation technique to study the effect on these polymers on floating behaviors. The physicochemical properties of different formulations, their buoyancy lag time and total floatation time and swelling index were evaluated. It is found that the high viscosity grade polymers given better controlled release drug profile. The in vitro release studies (USP XXIII) indicated that the floating dosage forms containing (F9) HPMC K100M high viscosity grade polymer with calcium carbonate (effervescing compound) instead of sodium bicarbonate showed good drug release rate up to 12 h in comparison to other batches. The results indicate that gas powered hydrodynamically balanced tablets of ranitidine containing HPMC K100M provides a better option for controlled release action and improved bioavailability.

Keywords: Gastric Residence, Gas Generation, Swelling Index, HPMC, Floating Tablet.