ABSTRACT
Chitosan is a unique polysaccharide, a copolymer of glucosamine and N-acetyl glucosamine linked by β 1–4 glucosidic bonds obtained by deacetylation of chitin. This has applications in wide variety of pharmaceutical and non-pharmaceutical fields due to its non-toxic, biocompatible and biodegradable properties. But the limitation of this polymer falls with its poor solubility at low pH and many organic solvent, which was overcome by chemical modification of the initial skeleton. Hence, chitosan and its derivatives have been used for mucoadhesion, permeation enhancement, wound healing, vaccine delivery, gene delivery etc. Chitosan and its derivatives have also been used for development of various drug delivery systems like transdermal, ocular, hydrogels, microparticles, targeted delivery based on pH sensitivity to various parts of gastro-intestinal tract like sublingual, buccal, intestine, colon. The applicability of chitosan and its derivatives in drug delivery along with the products marketed, past and current research trends will be discussed in this chapter.
