Gastro Retentive Drug Delivery System (GRDDS)

Gastro retentive drug delivery system (GRDDS), these dosage forms are designed to achieve prolonged gastric residence time in controlled release manner. The floating drug delivery system (FDDS) also comes under the gastro retentive drug delivery system. These type of formulations helps to improve the solubility of poorly soluble drugs and enhances the bioavailability of the drug. In gastrointestinal tract the absorption of dosage form or drug molecule is a highly variable process. To overcome all these physiological problems Novel Drug Delivery System (NDDS) plays an important role. FDDS works on the principle of buoyancy (the tendency of an object or a molecule float in a fluid or the upward force that a fluid exerts on an object) which allows the drug to remain in the gastric environment for a prolonged period of time without rapid passing into the intestine. Floatation of a drug is due to bulk density less than gastric fluids and so, remain buoyant in the stomach for a prolonged period of time. Releasing the drug slowly at the desired rate and increase the bioavailability of narrow absorption window drugs. This review helps to know the floating drug delivery system principle, advantages and disadvantages, need for floating bilayer tablets, challenges in bi-layer tablet manufacturing and characterization and evaluation methods for bilayer floating tablets.