A Comprehensive Review On: Floating Microbeads for Gastroretentive Drug Delivery Systems

Floating microbeads are an advanced gastro-retentive drug delivery system designed to prolong gastric residence time and enhance the bioavailability of drugs that are primarily absorbed in the upper gastrointestinal tract. Conventional oral drug delivery systems often require frequent dosing due to rapid drug elimination and short biological half-life, leading to fluctuations in plasma drug concentration. Floating drug delivery systems overcome these limitations by maintaining the dosage form in the stomach for an extended period through buoyancy, thereby allowing sustained and controlled drug release. Floating microbeads are hollow, spherical, free-flowing particles typically ranging from 1–1000 μm in diameter and are prepared using various polymers such as sodium alginate, chitosan, gelatin, and other natural or synthetic materials. These systems employ different preparation techniques including ionotropic gelation, emulsion gelation, internal and external gelation, and polyelectrolyte complexation. Drug release from microbeads occurs mainly through diffusion, erosion, and osmotic mechanisms. Floating microbeads offer several advantages such as improved bioavailability, reduced dosing frequency, minimized side effects, and better patient compliance. This review highlights the concept of floating drug delivery systems, classification, mechanisms, preparation methods, polymers used, evaluation parameters, and pharmaceutical applications of floating microbeads in controlled drug delivery.