Formulation and Evaluation of Famotidine Gastro-Retentive Floating Matrix Tablets by Using Natural and Synthetic Polymers

Drugs that have narrow absorption window in the gastrointestinal tract (GIT) will have poor absorption. For these drugs, gastro retentive drug delivery systems offer the advantage in prolonging the gastric emptying time. Famotidine belongs to H2-receptor antagonist. It is used widely for the treatment of treatment of gastro-esophageal reflux disease (GERD) and gastric ulceration duodenal ulcer, stress ulcer. The low bioavailability (40-45 %) and short biological half-life (2.54.0 hrs) of Famotidine following oral administration favors development of a sustained release formulation. The rapid gastrointestinal transit could result in incomplete drug release from the drug delivery system above the absorption zone leading to poor bioavailability of the drug. The floating tablets were formulated using synthetic polymer like HPMC K15M and natural polymer like chitosan as the release retardant polymers, and sodium bicarbonate as the gas generating agent to reduce the floating lag time. The tablets were prepared by direct compression. The formulated tablets were evaluated for weight variation, hardness, friability, swelling index, floating lag time, total floating time and dissolution rate in pH 1.2. The floating tablets extended the drug release up to 12 h. The drugpolymer interaction was evaluated by Fourier transform infrared spectroscopy (FTIR). The FTIR study indicated the lack of drug-polymer interaction. The optimized formulation (F5), containing drug: HPMC K15M 200mg and Chitosan 75mg showed very good result and extended the release up to 12 h. The drug release from the optimized formulation followed Zero order kinetics and Korsmeyer Peppas equation. Sumit Gaikwad *1 , laxmi Jamagondi 2 , Baburao