Abstract

One of the main challenges in drug delivery field is the development of formulations or devices designed to allow the transport of a suitable amount of the active pharmaceutical substance to the site of action in the body, and improve its efficacy by controlling the rate, time and place of release. The distribution of the drug to tissues different than the target place is unnecessary, wasteful, and a potential cause of toxicity. Chitosan, a versatile hydrophilic polysaccharide derived from chitin, is a non-toxic, biocompatible and biodegradable polymer which has attracted significant scientific interest, for its fundamental role in the progress of drug delivery technology. This natural biopolymer has inspired the development of safe and effective drug carrier systems due to its unique physicochemical and biological characteristics. The cationic character, exclusive of the chitosan, is attributed to the primary amino groups in the main backbone, which make its surface positively charged under acidic conditions; an important requirement that has been responsible for the enhancement of the load capability, tailoring the release profile of the drug and increasing the solubility. This chapter focuses on the use of chitosan-based therapeutic systems, including particles, hydrogel, film and scaffolds, through various anatomical routes by which the drug may be introduced in human body, such as oral, nasal, ocular, transdermal and local administration.