Abstract
The development of innovative drug delivery systems, versatile to different drug characteristics with better effectiveness and safety, has always been in high demand. Chitosan, an aminopolysaccharide, derived from natural chitin biomass, has received much attention as one of the emerging pharmaceutical excipients and drug delivery entities. Chitosan and its derivatives can be used for direct compression tablets, as disintegrant for controlled release or for improving dissolution. Chitosan has been reported for use in drug delivery system to produce drugs with enhanced muco-adhesiveness, permeation, absorption and bioavailability. Due to filmogenic and ionic properties of chitosan and its derivative(s), drug release mechanism using microsphere technology in hydrogel formulation is particularly relevant to pharmaceutical product development. This review highlights the suitability and future of chitosan in drug delivery with special attention to drug loading and release from chitosan based hydrogels. Extensive studies on the favorable non-toxicity, biocompatibility, biodegradability, solubility and molecular weight variation have made this polymer an attractive candidate for developing novel drug delivery systems including various advanced therapeutic applications such as gene delivery, DNA based drugs, organ specific drug carrier, cancer drug carrier, etc.