Development, In-vitro Evaluation & Study of Effect of Hardness on Buoyancy Time of Gastro retentive Floating Tablets of Famotidine

Gastro retentive drug delivery systems are the systems which are retained in the stomach for a longer period of time and thereby improve the bioavailability of drugs. Different approaches for gastroretentive dosage forms include floating, raft, expanding or swelling, bioadhesive or mucoadhesive and high/low-density systems.Famotidine, an anti-ulcer drug, suffers from poor bioavailability (50%), as famotidine is very less soluble in alkaline pH. Famotidine used in combination with antacids promotes local delivery of these drugs to the receptor of the parietal cell wall. Local delivery also increases bioavailability at the stomach wall receptor site and increases the efficacy of drugs to reduce acid secretion. Thus, the present work is aimed to formulate floating tablets of famotidine using an effervescent approach for gastroretentive drug delivery system.Floating tablets were prepared using directly compression technique using polymers like HPMC K4M and HPMCK100M for their gel-forming properties. The HPMC alone polymer unable to controlled release rate. It release drug >90% in 4-6 hrs while in combination with Xanthan gum it release >90% in 8 hrs. The results indicate that gas generated gastroretentive floating tablets of famotidine containing HPMCK100M and Xanthan gum provides a better option for controlled release action and improved bioavailability.