With the GRDDS, the dose shape remains controllably in the stomach after oral administration, so that the medication may be continually delivered to its absorption receptors in the intestinal tract. The medicine is delivering in a controlled and extended way. Gastro-retentive dose in the stomach area may last for another few hours and substantially lengthen the gastric residence period of the medicines. While the bulk density in the system for the supply of floating medicines (FDDS) exceeds the gastric fluids, it remains for an extended duration in the stomach without altering the rate of decomposition. The medication distributes gradually as the system floats on the stomach juice. As a consequence, stomach residency takes longer and plasma concentrations are well monitored. The therapy of peptic ulcer illness might be beneficial for local activity in the upper portion of the intestine, i.e., a longer stomach residency. In addition, medicines rapidly absorbed in the GI tract will increase bioavailability through delayed stomach release. The regulated gastric retention of solid dose forms can also be accomplished by the simultaneous administration of pharmacological agents, or by sedimentation, flotation processes, muco-adhesion, expansion, changed shape systems, by delaying the stomach emptying.
 Keywords: Gastro-retentive drug delivery system, Floating drug delivery system, Muco-adhesion, Bioavailability.