Daniel Argilashki, Yordanka Uzunova
Chitosan is a natural polysaccharide used in the pharmaceutical industry and medicine due to its hydrophilic, biocompatible, biodegradable, and non-toxic properties. However, it is insoluble in water, which limits its applications. Therefore, various chemical modifications of chitosan have been developed, offering improved biocompatibility, bioactivity, biodegradability, and non-toxicity while retaining its pharmacological effects. Chitosan has various derivatives, including carboxymethylated, acylated, quaternary ammonium, and thiolated forms. In addition to improving the physical and chemical properties of chitosan, these derivatives are also used as drug delivery systems. Studies have been conducted on the immobilization of drugs such as selegiline, doxorubicin, and tobramycin to modify chitosan. This review aims to highlight the advantages of chemical modification of chitosan and to encourage further research in this still vast area, as chemically modified chitosans have shown promising potential for application in various fields of medicine, pharmacy, and industry.