Srikrishna.T*, S.Sudheer, Sk.Mubashira, MD.Nayeem, P.V.Prasad
Drugs with narrow absorption window in gastrointestinal tract (GIT) is limited to poor bioavailability with conventional dosage forms due to incomplete drug release and short residence time at the site of absorption. In-situ gel provides the best way to overcome the complications raised in immediate release dosage forms and for the dosage forms that have short gastrointestinal residence time. Floating in-situ gel is a liquid before administration and when it comes in contact with gastric contents, solution converts into gel and floats on gastric contents. The formation of gel depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation from which the drug gets released in a sustained and controlled manner. Many natural, biodegradable, biocompatible and synthetic polymers like alginic acid, pluronic F127, xyloglucan, gellan gum, carbopol, pectin, chitosan, poly (DL lactic acid), poly (DL-lactide-coglycolide) and poly-caprolactone etc. are used in the preparation of in-situ gelling system. In-situ gels can be fabricated for both local and systemic therapy, where drug show therapeutic effect at the targeted site. This review gives a brief idea about advantages, limitations, mechanism of gelation, polymers used, method of preparation, evaluation and recent advancements of floating oral in-situ gels.
In-situ gel, Floating drug delivery system, Simulated gastric fluid, Polymers etc