ABSTRACT:
Oral drug delivery is considerably the most preferable route of drug delivery due to ease of administration, patient compliance and flexibility in formulation. A most important limitation in oral controlled drug delivery system is that many drugs are not absorbed uniformly throughout the gastro intestinal tract (GIT) some of them are absorbed in a particular section of GIT only or are absorbed to a different extent in various segments of GIT and diminished their bioavailability. Floating drug delivery systems have a bulk density less than gastric fluids and so, remain float on the stomach for a prolonged period of time and release the drug slowly at the desired rate from the system and increase the bioavailability of narrow absorption window drugs. The floating property depends on the density of a dosage form which affects the gastric emptying rate. A buoyant dosage form is believed to have a density of less than that of the gastric fluids floats. This review also summarizes the in-vitro techniques and in-vivo studies to evaluate the performance of these systems.