ABSTRACTThe oral route is a strategy that has been in use for many years. Although it is the most popular and widely used method for giving drugs to people orally, various restrictions, such as drug absorption or drug targeting to a specific 1organ, might make it difficult to administer... To address these issues as well as to advance medication development security and effectiveness In-situ Nasal Delivery is a unique method for medication delivery system for delivering drugs. The medication used in nasal gels is given as a low viscosity solution. The nasal mucosa when in contact with the polymer’s conformation transforms to a gel-like state. It is appropriate to use the nasal gel formulation for medications whose oral administration is challenging. Various biodegradable polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DLlactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. Keywords: In situ gel, bioavailability , polymers, nasal drug delivery.