Preparation and characterization of a novel pH-sensitive coated microsphere for duodenum-specific drug delivery.
The aim of this study is to develop a duodenum-specific drug delivery system on the basis of a pH-sensitive coating and a mucoadhesive inner core for eradication of Helicobacter pylori (H. pylori) in the ulcer duodenum. Hydroxypropyl methylcellulose acetate maleate (HPMCAM) was used as the pH-sensitive material, which dissolves around pH 3.0. The mucoadhesive microspheres loaded with furazolidone (FZD-ad-MS) were prepared by the emulsification-solvent evaporation method using Carbopol 971NP as the mucoadhesive polymer. The prepared pH-sensitive coated mucoadhesive microspheres (AM-coated-MS) were characterized in regards to particle size, drug loading efficiency, morphological change, drug stability, drug release and in vitro anti-H. pylori activity. The particle size was 160.97 ± 47.24 μm and 336.44 ± 129.34 μm, and the drug content was 42.33 ± 3.43% and 10.96 ± 1.29% for FZD-ad-MS and AM-coated-MS, respectively. The morphological changes in different pH media were characterized by scanning electron microscopy (SEM). HPMCAM coating improved the stability of the FZD-ad-MS and these particles were expected to remain intact until their arrival in the duodenum. The drug release was extremely suppressed at pH 1.2 for AM-coated-MS, but increased at pH 4.0 after regeneration of FZD-ad-MS. In addition, FZD-ad-MS exhibited excellent anti-H. pylori activity in vitro. Thus, the HPMCAM-coated microspheres developed in this study hold great promise for use as a duodenum-specific drug delivery system for H. pylori clearance.
Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, China.
Dan
D
Zhou
Xi
X
Zhu
Yang
Y
Wang
Yun
Y
Jin
Xuefan
X
Xu
Tingting
T
Fan
Yan
Y
Liu
Zhirong
Z
Zhang
Yuan
Y
Huang
D000818:Animals; D016503:Drug Delivery Systems / Q000379:methods*; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D065347:Hypromellose Derivatives; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D008747:Methylcellulose / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry; D008863:Microspheres; D010316:Particle Size; D013552:Swine; D014014:Tissue Adhesives / Q000008:administration & dosage* / Q000737:chemistry*; D014961:X-Ray Diffraction
D014014:Tissue Adhesives; D065347:Hypromellose Derivatives; D008747:Methylcellulose