FORMULATION AND EVALUATION OF GASTRO-RETENTIVE FLOATING TABLETS: A COMPARATIVE REVIEW OF SELECTED DRUG

Oral drug delivery is the most used route for drug administration because it is convenient, cost-effective, and well accepted by patients. However, conventional oral dosage forms often face challenges such as variable gastric emptying time, limited residence in the stomach, and incomplete drug absorption, particularly for drugs that are mainly absorbed in the upper part of the gastrointestinal tract. Gastro-retentive drug delivery systems (GRDDS) have been developed to overcome these limitations by prolonging the gastric residence time of the dosage form and improving drug absorption. Among the various GRDDS approaches, floating drug delivery systems (FDDS) have received significant attention due to their ability to remain buoyant in gastric fluid for an extended period while releasing the drug in a controlled manner. Floating tablets are commonly formulated using hydrophilic polymers such as hydroxypropyl methylcellulose & sodium alginate along with gas-generating agents that help maintain buoyancy. Various preparation techniques including direct compression, wet granulation, and dry granulation are used in the formulation of floating tablets. These formulations are evaluated using several parameters such as floating lag time, total floating duration, hardness, friability, drug content uniformity, swelling index, and in-vitro drug release studies. Floating drug delivery systems offer advantages such as prolonged gastric retention, sustained drug release, improved bioavailability, and reduced dosing frequency. However, certain limitations such as dependence on gastric fluid volume and variability in gastric motility may affect their performance. Overall, floating drug delivery systems represent a promising approach for improving the therapeutic effectiveness of drugs that exhibit narrow absorption windows or require prolonged gastric retention.