A COMPREHENSIVE REVIEW ON GASTRO RETENTIVE DRUG DELIVERY SYSTEM

Gastro-retentive drug delivery systems (GRDDS) are advanced oral delivery approaches designed to prolong gastric residence time and improve the therapeutic performance of drugs with site-specific absorption or gastric activity. Conventional dosage forms may undergo rapid gastric emptying, resulting in incomplete absorption, variable bioavailability, and reduced therapeutic efficacy. GRDDS overcome these limitations by maintaining the dosage form in the stomach and providing controlled or sustained drug release. Major approaches include floating, expandable, swellable, mucoadhesive, high-density, raft-forming, and magnetic systems. Their performance depends on formulation and physiological factors such as dosage-form density, size, shape, polymer properties, gastric motility, and fed or fasted state. This review summarizes the principles, classification, formulation strategies, mechanisms of gastric retention, preparation methods, evaluation parameters, therapeutic applications, advantages, limitations, and recent advances in GRDDS. Overall, GRDDS offer a promising strategy for improving drug absorption, bioavailability, therapeutic efficacy, and dosing convenience.