FLOATING DRUG DELIVERY SYSTEMS: A COMPREHENSIVE REVIEW ON FORMULATION, CHARACTERIZATION, AND THERAPEUTIC APPLICATIONS

Floating drug delivery systems (FDDS), also referred to as gastro retentive drug delivery systems (GRDDS), are oral dosage forms designed to prolong gastric residence time, improving the absorption and bioavailability of drugs with narrow absorption windows or local gastric activity. FDDS employ mechanisms such as effervescence, swelling, low-density matrices, and bioadhesion to remain buoyant in gastric fluids. This review comprehensively discusses mechanisms of floating, formulation strategies, polymers and excipients, characterization parameters, and therapeutic applications. Techniques including effervescent and non-effervescent systems, raft-forming systems, floating microspheres, and bio adhesive floating systems are elaborated. Key evaluation parameters such as buoyancy lag time, total floating time, in vitro release, swelling index, density, and stability studies are described. Therapeutic applications of FDDS in anti-ulcer, antihypertensive, antidiabetic, and cardiovascular therapy are highlighted. Challenges such as high-density drugs, variability in gastric emptying, formulation complexity, and scale-up are discussed. Recent advances, including floating nanoparticles, microcapsules, and 3D-printed gastro retentive systems, promise personalized and efficient drug delivery. FDDS remain a promising platform for enhanced oral bioavailability, controlled release, and patient compliance.