In situ gelling systems of chitosan for potential drug delivery applications

Chitosan, a natural polymer, is basically an amino polysaccharide and is usually isolated from chitin (cellulose-like polymer) through deacetylation (alkaline medium). The chitosan-based systems, due to its biodegradability, biocompatibility, mucoadhesiveness, antiinfective properties, permeation enhancers, and wound healing activities, have found significant importance in pharmaceutical and biomedical applications. Moreover, the amalgamation of chitosan with specific stimuli-responsive polymers could potentially increase therapeutic efficacy of the formulations. The in situ gelling systems are considered to be as a novel category delivery system which are usually composed of either a natural, synthetic, or semisynthetic polymers and exhibits the distinctive characteristic of sol–gel transformation in the presence of a specific biological stimuli. In recent times, great consideration has been put over the chitosan-based in situ gel-forming delivery systems as these systems not only are found to be biocompatible and biodegradable, but also exhibits least or no toxicity. In this review, we have discussed the therapeutic applications of various established chitosan-based in situ gelling systems.