|Chitosan is a linear polysaccharide composed of randomly distributed ß-(1-4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). Chitosan is a partially deacetylated polymer of N-acetyl glucosamine. It is essentially a
natural, water-soluble, derivative of cellulose with unique properties. Chitosan is an amino polysaccharide that has the ability to "bind" lipids in the stomach before they are absorbed through the digestive system into the bloodstream. Chitosan is a biodegradable cationic biopolymer achieved by the extensive deacetylation of chitin obtained from prawn shell waste. Chitosans are biopolymers which belong to the group of hydrocolloids. In contrast to most hydrocolloids, which are negatively charged at biological pH values, chitosans are cationic biopolymers under these conditions.
Chitosan is a dietary fiber derived from chitin. Chitin is typically prepared from waste shells of crustaceans, particularly decapod crustaceans such as crab, shrimp, crawfish, krill, lobster, squid and prawn. Removal of acetyl groups from the chitin polymer (deacetylation) produces chitosan. Chitosan is not a single, definite chemical entity since it varies in composition depending on the crustacean species used for the starting material and the particular preparation method used. Reducing or substantially removing impurities from chitosan that can cause immunological reactions is critical for chitosan intended for use as a biocompatible and biodegradable material in medical applications. Chitin and chitosan refer to a family of compounds that exhibit widely differing physical and chemical properties. These differences are due primarily to the products' varying molecular weights, degrees of acetylation and presence of contaminants such as covalently bound, species-specific proteins, single amino acid and inorganic contaminants.