Floating Oral In-Situ Gel: A Review

Abstract

The drugs having a narrow absorption window in the gastrointestinal tract (GIT) when administered by oral route are often limited by poor bioavailability due to incomplete drug release and short residence time at the site of absorption. Novel drug delivery systems in the form of gastroretentive systems such as floating systems, mucoadhesive, high-density, expandable have been developed as they provide controlled delivery of drugs with prolonged gastric residence time. Liquid orals are more prone to low bioavailability because they are eliminated quickly from the stomach since they are subjected to faster transit from the stomach/ duodenum. The problems of immediate release and short gastrointestinal residence of liquids are eliminated by formulating as oral in situ gels as they provide the best means to overcome these problems The in situ gel dosage form is a liquid before administration and after it comes in contact with gastric contents due to one or more mechanisms gets converted to gel which floats on gastric contents. This achieves increased residence as well as sustained release. This approach is useful for systemic as well as local effect of drugs administered. This review gives a brief idea about floating oral in-situ gel formation and research done by various scientists on a number of drugs and polymers.
 Keywords: Floating drug delivery, gastric retention time, In-situ gel.