FORMULATION AND EVALUATION OF FLOATING MICROSPHERES OF FAMOTIDINE HYDROCHLORIDE.

Controlled release gastric floating drug delivery system has a bulk density less than gastric fluids, so it remain buoyant in the stomach without affecting the gastric emptying rate for prolonged period of time. There by releasing the drug for prolonged period of time constantly to the upper part of the GIT and improves the bioavailability of drug with narrow absorption window. Famotidine is a histaminic drug that has been widely used in treating gastric and duodenal ulceration and also in zollinger elison syndrome and reflux oesophagitis. It works by reducing swelling and constricting blood vessels in the GIT passage, allowing you to get relief from gastritis easily. Floating microspheres are gastro-retentive drug delivery system. These microspheres are free flowing powders, gastric contents for prolonged time. Hence faster dissolution of dosage form results in faster absorption and onset of action. Floating microspheres are absorbed from mouth, pharynx and esophagus as the saliva passes down the stomach. In such cases the bioavailability is greater than those observed for conventional dosage form. Different polymers such as ethyl cellulose, sodium alginate were optimized with different concentration and varying the ratios in order to get the sustained release profile over a period of 24 hrs. All the formulations were evaluated for in-vitro buoyancy, entrapment efficiency and in-vitro drug release profile. The results revealed that the present buoyancy is more than 70% after 24 hrs. The mean particle size of microspheres was in the range of 102.33-420.53 ?m. In-vitro release of floating microspheres of Famotidine HCL was found to be in following order,H1>HE1>H2>HE4>E1>HE2>H3>HE3>HE5>E2>E3. H1 was found to be the best formulation among all other formulation prepared as it release Famotidine HCL 98.84 % in a sustained manner with constant fashion over extended period of time (after 24 hr).