Chitosan: A Biocompatible Material for Oral and Intravenous Administrations

Abstract

Chitosan is the N-deacetylated product of chitin {(1→4)-linked 2-acetamido-2-deoxy-β-D-glucan}, which is abundant in nature. (1) No abnormal symptom was observed with several animals when chitosan was orally administered at a dosage of 0.7–0.8 g/kg body weight/day for up to 239 days. (2) Apparent digestibility by rabbits was 28–38% for chitin and 39–79% for chitosan, and that both polymers were digested almost completely by hens and broilers. (3) No abnormal symptom was observed with rabbits when low-molecular-weight (LMW)-chitosan (MW about 3,000) or chitosan oligosaccharides (MW 304 – 1,162) were injected intravenously at a dosage of 4.5 mg/kg body weight/day for 7–11 days. (4) Hypocholesterolemic function was observed with chitosan administered orally but not with LMW-chitosan or oligosaccharides injected intravenously. These data strongly indicate that chitosan is usable as a novel carrier of drugs in the drug delivery system for oral and intravenous administration.