Chitosan as potential carrier for drug delivery

This chapter addresses one of the most researched biodegradable polycationic polymers, chitosan. Its unique properties, including biocompatibility, low allergenicity, non-toxicity, and biodegradability, enable it to be used in a wide range of applications. Chitosan is a linear polysaccharide derived from chitin through partial deacetylation and made up of a spontaneous distribution of β-(1–4)-linked D-glucosamine and N-acetyl-D-glucosamine. Due to the presence of primary amino groups, chitosan has a cationic character. In an acidic environment, the majority of polysaccharides are neutral or negatively charged, so chitosan’s cationic nature is unusual and proved to enhance permeation, mucoadhesion, in situ gelling, and efflux pump inhibition activity. Moreover, using ionic interactions, controlled drug release, nanoparticulate delivery systems for DNA-based drugs, and much more can be accomplished. A significant amount of research on chitosan and its future application in drug delivery systems has been conducted in recent years. There is a growing interest in sustained/controlled and tailored dosage forms that can have improved patient compliance, customized, and effective therapeutic results. Here we provide a comprehensive review and the latest developments on chitosan and its derivatives as novel drug carriers.