Formulation and Evaluation of in situ Gel System for Targeted Drug Delivery System

Abstract

The present study was aimed at the development of stomach specific drug delivery systems using natural polymer. It concerns with the development and optimization of a formulation of in-situ gel of famotidine. It is H2 receptor antagonist absorbed from the upper gastrointestinal tract and it is preferentially localized in parietal cells of gastric mucosa. The polymer used in the study is locust bean gum and sodium alginate. Locust bean gum forms a layer on the surface of gastric mucosa and prevents irritation due to free Na+ ions of sodium alginate whereas sodium alginate forms gel when it comes in contact with simulated gastric fluid. The principle of gelling involves supply of complexed calcium ions in form of calcium carbonate that are released in the acidic environment of the stomach. Nine different formulations were prepared by varying concentration of locust bean gum sols and calcium carbonate in demonized water where as the concentration of sodium alginate and tri-sodium citrate remain constant. The amount of drug is kept constant for all nine formulations. From the result we found that F6 formulation showed optimum drug release. The % drug release from the optimized formulation was found to be 98.9 % after 24 hrs and viscosity 28.7 centipoises, thus batch F6 was selected as an optimized formulation because it shows more controlled release, which exhibited a drug content of 97.8 % and has a floating time of more than 24 hrs. Stability study was done according to ICH guidelines. newline