title: Synthesis and characterization of HPMC derivatives as novel duodenum-specific coating agents.
abstract: HPMC (Hydroxypropyl methylcellulose) was chemically modified, using maleic anhydrides, to obtain pH-sensitive HPMCAM (Hydroxypropyl methylcellulose acetate maleate) polymers for use as novel duodenum-specific coating agents. The pharmaceutical properties of HPMCAM, such as film forming, acid values, pH-sensitive values, water vapor permeability, tensile strength and Tg, were investigated, and found to show good film forming properties. The pH-sensitive values were 3.0 to 3.7. In vitro results demonstrate that HPMCAM could completely suppress drug release within 2h in a simulated gastric fluid (pH 1.2) and rapidly release the drug in a simulated pathological duodenal fluid (pH 3.4). These results indicate that HPMCAM might be a useful material for a duodenum-specific drug delivery system.
authors.affiliation: Key Laboratory of Drug Targeting and Novel Drug Delivery Systems, West China School of Pharmacy, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu 610041, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huang
authors.forename: Ling-li
authors.initials: LL
authors.lastname: Zheng
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Zhi-rong
authors.initials: ZR
authors.lastname: Zhang
mesh_terms: D001599:Berberine / Q000145:classification; D016503:Drug Delivery Systems; D004386:Duodenum; D006863:Hydrogen-Ion Concentration; D065347:Hypromellose Derivatives; D007700:Kinetics; D008299:Maleic Anhydrides / Q000737:chemistry*; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry*; D010539:Permeability; D013607:Tablets; D013678:Technology, Pharmaceutical; D013718:Tensile Strength; D044366:Transition Temperature; D014867:Water
chemical_list: D008299:Maleic Anhydrides; D013607:Tablets; D014867:Water; D001599:Berberine; D065347:Hypromellose Derivatives; D008747:Methylcellulose