Effect of Effervescent Agents on the Formulation of Famotidine Loaded Sodium Alginate Floating Beads


Famotidine is histamine H2 receptor antagonist; it is widely used in treatment of gastric ulcer and gastroesophageal reflux disease. The low bioavailability (40-45%), short biological half life (2.5-4 hrs) of famotidine in addition to have an absorption window, this favor the development of controlled release gastroretentive dosage forms of the drug. In this study, the floating beads of famotidine by ionotropic gelation technique were formulated in two different combinations such as sodium alginate withhydroxypropyl methyl cellulose(HPMC) and sodium alginate with guar gum. The effect of CO2 gas forming agents such as CaCO3 or NaHCO3 on drug loading, % drug entrapment efficiency, floating properties and invitro drug release were evaluated. It was found that as the ratio of gas forming agents increased from 0.2 to 1 , the floating property was increased for both type of gas forming agents while % entrapment efficiency of famotidine beads are decreased from 86.11 % to 68.5% for CaCO3 and from 84.3% to 60.7% for NaHCO3 . Increasing the CaCO3 ratio did not appreciably accelerate drug release as compared with NaHCO3, indicating that CaCO3 is superior to NaHCO3 as gas forming agent in floating beads of famotidine. On the other hands, beads containing guar gum produce more sustained release of famotidine than that beads containing HPMC.Furthermore, the release mechanism were investigated and the results indicate that most of the formulations follow Higuchi modelwith non fickian anomalous drug release behavior.