Floating Microspheres as Gastro-Retentive Drug Delivery System: A Review

Gatsroretentive drug delivery system offers several advantages besides providing better bioavailability to poorly absorbed drugs and a required release profile thus attracting interest of pharmaceutical formulation scientists. A controlled drug delivery system with prolonged residence time in the stomach can be of great practical importance for drugs with an absorption window in the upper small intestine. Various gastroretentive dosage forms are available, including tablets, capsules, pills, laminated films, granules and powders. Floating microspheres is one among the several approaches to gastroretention, like mucoadhesion, flotation, sedimentation, expansion, modified shape systems etc. Floating microspheres have been gaining attention due to the uniform distribution of these multiple-unit dosage forms in the stomach, which results in more reproducible drug absorption and reduced risk of local irritation. Such systems have more advantages over the single-unit dosage forms. The present review briefly addresses the physiology of the gastric emptying process with respect to floating drug delivery systems. The purpose of this review is to bring together the recent literature with respect to the method of preparation, and various parameters affecting the performance and characterization of floating microspheres.