title: A novel pH-enzyme-dependent mesalamine colon-specific delivery system.
abstract: The aim of the present study was to design a new pH-enzyme double-dependent mesalamine colon-specific delivery system. The drug release behaviors in vitro and pharmacokinetics and biodistribution in vivo were further evaluated. The mean particle diameters of mesalamine-coated microparticles were 312.2 µm. In vitro, a small amount of mesalamine was released in HCl at a pH of 1.2 and PBS medium at a pH of 7.4 for 5 hours, and 71% of the entrapped mesalamine was further released during the subsequent 20 hours of incubation. A greater area under the plasma concentration-time curve (AUC)0-t was obtained for the coated microparticles (1.9-fold) compared to the suspensions group, which indicated that the encapsulated mesalamine had mostly been absorbed in rats over the period of 12 hours. The AUC0-t of the coated microparticles in colon was 2.63-fold higher compared to the suspensions (P<0.05). Hence, mesalamine-coated microparticles are considered to maintain the drug concentration within target ranges for a long period of time.
authors.affiliation: Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.affiliation: Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Yi-Cun
authors.initials: YC
authors.lastname: Ding
authors.affiliation: Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Xu
authors.affiliation: Department of Gastroenterology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Cao
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D003106:Colon / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D065546:Drug Liberation; D005260:Female; D006863:Hydrogen-Ion Concentration; D008297:Male; D019804:Mesalamine / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D051379:Mice; D010316:Particle Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D014018:Tissue Distribution
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D019804:Mesalamine
keywords: biodistribution; colon specific; mesalamine; pH-enzyme; pharmacokinetics