ABSTRACT:
Chitosan is a functional linear biopolymer and can be derived by partial deacetylation of chitin. It is the most abundant natural polysaccharide on the earth after cellulose and can be obtained from exoskeleton of marine crustaceans such as crabs, lobsters, shrimps and krill. Chitosan is currently gaining a great deal of attention for medical applications as well as for the controlled release particulate drugs delivery system. Because of its excellent properties such as non-toxicity, biocompatibility, mucus-adhesion, enzymatic biodegradability and biodegradation, chitosan has been developed for a variety of biomedical applications including wound dressings and drug delivery systems. In the last decade it has been proven that chitosan was a useful excipient, and it can be formed to microspheres with many kinds of drugs and vaccines. Chitosan-based drug delivery systems of microspheres for various vaccines have been developed such as influenza, pertussis and diphtheria antigens. Chitosan microspheres have been widely investigated for use as controlled release delivery systems for hormones, vitamins, proteins, enzymes and different active pharmaceuticals.