CHITOSANS VERSUS THIOLATED CHITOSANS AS POLYMERS IN MUCOADHESIVE DRUG DELIVERY - A COMPARITIVE STUDY

Abstract

The bio polymer chitosan is obtained by alkaline deacetylation of chitin, which is one of the most abundant polysaccharides in nature. Chitosan is a polysaccharide consisting of co polymers of glucosamine and N-acetyl glucosamine. Recently it has been shown that polymers with thiol groups provide much higher adhesive properties than polymers generally considered to be mucoadhesive. The enhancement of muco adhesion can be explained by the formation of covalent bonds between the polymer and mucous layer which is stronger than non-covalent bonds. Thiolated chitosans show more advantages than that of chitosans even though their cost of production is more than that of chitosans.The insitu gel formation within the pH range of 5 to 6.8 makes the application of thiolated chitosans on vaginal, nasal and ocular mucosa also possible.