Chitosan is the deacetylated form of chitin. Generally, the substance becomes
soluble in dilute acids when the degree of deacetylation is more than 50%. The
solubility of chitosan in dilute acids is often needed to be modified when
specific drug release properties have to be tailored into the dosage form. The
available toxicological data on chitosan and its modified forms appears to
indicate its safety for oral use because high doses have been found to be
tolerated well in rodents and rabbits. However, its local action as a
haemostatic together with its ability to activate macrophages and cause cytokine
release may require a careful assessment of its