title: Preparation and swelling properties of pH-sensitive composite hydrogel beads based on chitosan-g-poly (acrylic acid)/vermiculite and sodium alginate for diclofenac controlled release.
abstract: A series of pH-sensitive composite hydrogel beads, chitosan-g-poly (acrylic acid)/vermiculite/sodium alginate (CTS-g-PAA/VMT/SA), was prepared using CTS-g-PAA/VMT composite and SA by Ca(2+) as the crosslinking agent. The structure and morphologies of the developed composite hydrogel beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling properties and pH-sensitivity of the beads were investigated. In addition, the drug loading and controlled release behaviors of the beads were also evaluated using diclofenac sodium (DS) as the model drug in stimulated gastric fluids (pH 2.1) and intestinal fluids (pH 6.8). The results indicate that the composite hydrogel beads showed good pH-sensitivity. The release rate of the drug from the composite hydrogel beads is remarkably slowed down, which indicated that incorporating VMT into the composite hydrogel beads can improve the burst release effect of the drug.
authors.affiliation: Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Road 18#, Lanzhou 730000, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xie
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhang
authors.forename: Junping
authors.initials: J
authors.lastname: Zhang
authors.forename: Aiqin
authors.initials: A
authors.lastname: Wang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000464:Alginates / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000494:pharmacology; D004008:Diclofenac / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000180:Acrylic Resins; D000464:Alginates; D000538:Aluminum Silicates; D003692:Delayed-Action Preparations; D006603:Hexuronic Acids; C065246:chitosan-poly(acrylic acid); C003760:vermiculite; D004008:Diclofenac; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid; D048271:Chitosan