title: pH-sensitive and mucoadhesive microspheres for duodenum-specific drug delivery system.
abstract: Particulate systems that could deliver drug specifically to duodenum have not yet been reported. The aim of this study was to develop a novel duodenum-specific drug delivery system based on thiolated chitosan and hydroxypropyl methylcellulose acetate maleate (HPMCAM) for the duodenal ulcer application. Berberine hydrochloride was used as model drug. Thiolated chitosan was synthesized and further used for the preparation of mucoadhesive microspheres. HPMCAM, which is insoluble below pH 3.0 was synthesized and used for the coating of thiolated chitosan microspheres (TCM). The resulting thiolated chitosan immobilized on chitosan was 268.21 ± 18 μmol/g. In vitro mucoadhesion study showed that the mucoadhesion property of TCM was better than that of chitosan microspheres. Morphological observation showed that the HPMCAM coating would maintain its integrity in simulated gastric fluid (SGF) for 2 h and dissolved quickly in simulated pathological duodenal fluid (SPDF; pH 3.3). In vitro drug release studies showed that only 4.75% of the drug was released in SGF for 2 h, while nearly 90% of the drug was released within 6 h after transferring into SPDF.
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, PR China.
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Zhu
authors.forename: Dan
authors.initials: D
authors.lastname: Zhou
authors.forename: Yun
authors.initials: Y
authors.lastname: Jin
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Zhao
authors.forename: Zhi-Rong
authors.initials: ZR
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000268:Adhesiveness; D001599:Berberine / Q000008:administration & dosage; D048271:Chitosan; D016503:Drug Delivery Systems / Q000379:methods*; D004381:Duodenal Ulcer / Q000188:drug therapy; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D065347:Hypromellose Derivatives; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D008747:Methylcellulose / Q000031:analogs & derivatives; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D013608:Tablets, Enteric-Coated
chemical_list: D013608:Tablets, Enteric-Coated; D001599:Berberine; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D048271:Chitosan