Famotidine (FMT) is known as a histamine blocker (H2) that inhibits stomach acid production and it is commonly used in the treatment of peptic ulcer disease and gastric-esophageal reflux disease. It has a short half life (2.5-3.5 hours), low bioavailability (40-45%). It has excellent solubility in acidic pH just reverse in alkaline pH. Therefore an attempt has been made to develop raft buoyant gastro-retentive sustains release delivery system with in situ gelling property which is based on thixotropy behavior. Twelve formulations (Excluding two controlled formulations i.e. F and F* ) were designed to contain 40 mg of FMT using Chitosan; CH (cationic polymer), Sodium Alginate; SA (anionic polymer), Gelucire 43/01; G 43/01 (lipid phase) as retardant and adhesive polymers. Emulgel was prepared and evaluated for their physicochemical properties like buoyancy and lag time, cumulative % drug release, drug release kinetics and drug excipient interaction studies by thermal studies and functional group characterization. All formulations showed that with the increase in concentration of the polymer, the gel strength increased, but the % drug release decreased F8>F12>F11>F6>F5>F10>F7>F9>F3>F4>F1>F2>F*>F. Formulations F9, F10, and F12 were found to be optimum. They followed the non-ficikian mechanism of drug release.
Tiwari et al.