title: Preliminary studies on pH-sensitive hydrogels and in vitro release profiles of two model drugs.
abstract: The main aim of the present study was to develop a series of pH-sensitive hydrogels for targeted releasing drugs under simulated intestinal environment instead of stomach condition. These hydrogels were prepared via free radical polymerization with polyethylene glycol methacrylate 475 (PEGMA475), PEGMA950 and methacrylic acid as monomers, triethylene glycol dimethacrylate (TRGDMA), and ethylene glycol dimethacrylate as cross-link agents. The surface morphology and internal structures of hydrogels were detected by scanning electron microscope. The swelling experiments were also performed and the results revealed that the smart hydrogels were pH sensitive and their sensitiveness was reversible. Diclofenac sodium and bull serum albumin used as model drugs were loaded in the hydrogels to target releasing them in simulative intestinal tract. In vitro releasing studies showed that medicated hydrogels released model drugs slowly in acid conditions (pH 1.2), while the cumulated release amounts of drugs increased greatly when ambient pH value increased to 7.4. These phenomena indicated that these hydrogels tended to target release stimulating and destructible drugs in intestinal canal instead of gastric environment.
authors.affiliation: Chemical and Pharmaceutical Engineering Institute, Hebei University of Science and Technology, Hebei 050018, China. shangqingyl@163.com
authors.forename: Qing
authors.initials: Q
authors.lastname: Shang
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Liang
authors.forename: Yongli
authors.initials: Y
authors.lastname: Shi
mesh_terms: D000818:Animals; D002417:Cattle; D003432:Cross-Linking Reagents / Q000737:chemistry; D004008:Diclofenac / Q000737:chemistry; D004337:Drug Carriers; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D004337:Drug Carriers; D020100:Hydrogels; D008689:Methacrylates; D011109:Polymethacrylic Acids; D012709:Serum Albumin; C524499:polyethylene glycol methacrylate; D004008:Diclofenac; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C004919:ethylene dimethacrylate