title: In vivo application of chitosan to facilitate intestinal acyclovir absorption in rats.
abstract: The effect of chitosan on the intestinal absorption of acyclovir (ACV) was evaluated in rats, and factors influencing its facilitative effect on the ACV absorption were examined. When ACV solution containing 1% chitosan with an average molecular weight of 150 kDa was administered into the upper jejunum, a significant increase in the plasma ACV concentration was observed, with the peak ACV concentration being eight times greater than that observed with the chitosan-free solution. The chitosan-free ACV solution, whose viscosity was adjusted to remain unchanged with polyethylene glycol, did not cause an increase in the plasma concentration, and neither did the chitosan-free solutions substitutionally containing low molecular cationic compounds, triethanolamine and kanamycin. When chitosan was digested with chitosanase to shorten its polycationic polysaccharide structure, chitosan subjected to 150-min digestion retained its facilitative effect on ACV absorption, but that subjected to 420-min digestion no longer caused facilitation, in which its average molecular weight was reduced to around 10 kDa. It is therefore indicated that intestinal ACV absorption can be facilitated with chitosan, and that it is necessary for chitosan to have a certain length of polycationic polysaccharide structure to exert such facilitation.
authors.affiliation: Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima-Naka, Okayama 700-8530, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Masuda
authors.forename: Yuko
authors.initials: Y
authors.lastname: Goto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kurosaki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Aiba
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D048271:Chitosan / Q000737:chemistry* / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism; D008297:Male; D014677:Pharmaceutical Vehicles / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013302:Streptomyces / Q000201:enzymology; D014783:Viscosity
chemical_list: D000998:Antiviral Agents; D014677:Pharmaceutical Vehicles; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase; D000212:Acyclovir