title: Eudragit coating of chitosan-prednisolone conjugate microspheres and in vitro evaluation of coated microspheres.
abstract: Chitosan-prednisolone conjugate microspheres (Ch-SP-MS) were prepared, and Eudragit coating was applied in order to efficiently deliver the microspheres and drug to the intestinal disease sites. The Eudragit L100-coated microspheres (Ch-SP-MS/EuL100) were examined for particle characteristics and the release of drug and Ch-SP-MS in different pH media at 37 degrees C. Ch-SP-MS were spherical, with a mean size of 4.5 microm and prednisolone content of 3.3% (w/w). Ch-SP-MS/EuL100 were fairly spherical, with a mean size of 22. 5 microm and drug content of 0.32% (w/w). At pH 1.2, the release extent was less than 5% even at 48 h, and Eudragit coating tended to suppress the release. In contrast, at pH 6.8 and 7.4, Ch-SP-MS/EuL100 tended to show somewhat faster drug release than Ch-SP-MS. Ch-SP-MS/EuL100 displayed a release extent of 23 and 27% at pH 6.8 and 7.4, respectively. Ch-SP-MS aggregated at pH 1.2, but almost kept their initial size and shape at pH 6.8 and 7.4. Ch-SP-MS/EuL100 almost maintained their original shape and size at pH 1.2, and gradually released Ch-SP-MS at pH 6.8 and 7.4 due to dissolution of the Eudragit layer. Eudragit coating is suggested to be useful to efficiently deliver Ch-SP-MS to the intestinal disease sites.
authors.affiliation: Department of Drug Delivery Research, Hoshi University, Ebara, Shinagawa-ku, Tokyo, Japan. onishi@hoshi.ac.jp
authors.forename: Hiraku
authors.initials: H
authors.lastname: Onishi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Oosegi
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Machida
authors.forename: James W
authors.initials: JW
authors.lastname: McGinity
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000893:Anti-Inflammatory Agents / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D016503:Drug Delivery Systems; D005772:Gastrointestinal Transit; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D011239:Prednisolone / Q000737:chemistry*; D013608:Tablets, Enteric-Coated
chemical_list: D000179:Acrylates; D000893:Anti-Inflammatory Agents; C477020:Eudragit E100; D011108:Polymers; D013608:Tablets, Enteric-Coated; D048271:Chitosan; D011239:Prednisolone