title: Mucoadhesive DL-lactide/glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin.
abstract: The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.
authors.affiliation: Department of Pharmaceutical Engineering, Gifu Pharmaceutical University, Japan. yoshiaki@gifu-pu.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kawashima
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Kuno
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000284:Administration, Oral; D000464:Alginates / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002116:Calcitonin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D002118:Calcium / Q000097:blood; D002614:Chelating Agents / Q000494:pharmacology*; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan; D003692:Delayed-Action Preparations / Q000493:pharmacokinetics*; D004068:Digestive System Physiological Phenomena; D016503:Drug Delivery Systems / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D066298:In Vitro Techniques; D007440:Intubation; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D008863:Microspheres; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D013608:Tablets, Enteric-Coated; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D000464:Alginates; D001672:Biocompatible Materials; D002614:Chelating Agents; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; D011108:Polymers; D013608:Tablets, Enteric-Coated; D002686:Chitin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C006903:carbopol 940; D020723:Glucuronic Acid; D002116:Calcitonin; D048271:Chitosan; D016650:Fluorescein-5-isothiocyanate; D002118:Calcium; C012755:elcatonin