Formulation and Biopharmaceutical Evaluation of Gastro- Retentive Drug Delivery System of Anti-Ulcer Drugs (floating microspheres of famotidine)

Abstract

The floating drug delivery system or hydrodynamically balanced systems are among the several approaches that have been made developed in order to increase the gastric transit time of drug. The microspheres are characteristically free flowing powders consisting of natural or synthetic polymers and ideally having a particle size less than 200m. Microspheres incorporating a drug dispersed or dissolved throughout particle matrix have the potential for the controlled release of drug.Microspheres are one of the multiarticulate delivery system and are prepared to obtain controlled the drug release from the dosage form to improve bioavailability, reduces the adverse action and prolong the action of drug, reduce absorption difference in patients, reduce the dosing frequency and adverse effects during prolong treatment. It is needed to formulate in long-acting dosage form, reaching to effective biological site rapidly.Famotidine is H2 receptor antagonist which is used for ulcers thus by formulating it in the form of floating microspheres it will not only show targeted action but also shows sustainability and reduced dosing interval. Thus, by formulating it as a floating microsphere the targeted action can be achieved. Famotidine is formulated as floating microspheres by Solvent evaporation method is the preparation technique that is widely preferred for the preparation of controlled release microspheres. To prepare emulsion by adding the dispersed phase consisting of drug, polymer and appropriate dispersion agent in organic solvent to dispersion medium which is immiscible with the dispersed phase and Mini matrix forms are obtained by removing the solvent used at the dispersed phase from the droplets which are formed in the emulsion5, 6.The obtained microspheres of famotidine were subjected to various analytical techniques like Particle size analysis, SEM analysis, invitro dissolution studies and  stability studies.