Perspectives on: Chitosan drug delivery systems based on their geometries

Chitosan is a natural polymer that has many physicochemical (polycationic, reactive OH and NH2 groups) and biological (bioactive, biocompatible, biodegradable) properties. These unique properties make chitosan an excellent material for the development of new biomedical applications. One of the most well known biomedical chitosan applications is in drug delivery systems. Chitosans have been used in the design of many different types of drug carriers for various administration routes such as oral, bucal, nasal, transdermal, parenteral, vaginal, cervical, intrauterine and rectal. Chitosan can be engineered into different shapes and geometries such as nanoparticles, microspheres, membranes, sponges and rods. This paper is a perspective on the preparation of the chitosan drug delivery systems based on different structural geometries. In this respect, special preparation techniques are used to prepare chitosan drug carriers by altering such parameters as crosslinker concentration, chitosan molecular weight, drug/polymer ratio and processing conditions all of which affect the morphology of chitosan drug carriers and release rate of the loaded drug.