FORMULATION AND EVALUATION OF GASTRO-RETENTIVE FLOATING MICRO-SPHERES: A SYSTEMATIC REVIEW

Gastro-retentive drug delivery system is the novel controlled release system that overcomes the problem like the first-pass metabolism, narrow index of absorption, unstable in intestinal pH, low bioavailability. Different approaches to GRDDS are floating, mucoadhesive, swelling, high density, magnetic drug delivery system. The floating drug delivery system is the most promising approach. The dosage forms remain buoyant for a longer duration of time in the gastric fluid due to the low density of dosage form. Gastric residence time is increased. In this system, there is site-specific drug delivery in the upper part of GIT. Drug release is a slow and controlled manner; drug absorption is increased. The bioavailability of drug is enhanced. Floating microspheres are gaining attention because it remains buoyant for longer time and uniform distribution of drug over the gastric fluid. Fluctuation in plasma drug concentration is reduced. Gastro-retentive dosage form prolong dosing interval reduce the frequency of drug administration so increase in patient compliance. GRDDS is useful for sustained/controlled drug delivery. This article gives an overview of different gastro-retentive systems, suitable drug candidates for GRDDS, advantages, and disadvantages, factors affecting GRDDS, floating microspheres, methods of preparation, evaluation, and application. Also, this review includes different studies on floating microspheres by various researchers.