Polyelectrolyte Complexes Based on Chitosan and Natural Polymers

Abstract

For many years chitosan has been the subject of interest for its use in different medical fields due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. Chitosan is positively charged at low pH values, so it is spontaneously associated with negatively charged polyions in solution to form polyelectrolyte complexes. These chitosan based polyelectrolyte complexes exhibit favourable physicochemical properties with preservation of chitosan’s biocompatible characteristics. These chitosan based complexes are a good candidate for excipient materials for the design of different types of dosage forms. The aim of this review is to describe polyelectrolyte complexes of chitosan with selected natural polyanions and also to indicate some of the factors that influence the formation and stability of these formed complexes.