title: Poly (vinyl alcohol)/SiO2 composite microsphere based on Pickering emulsion and its application in controlled drug release.
abstract: In this paper, with W/O Pickering emulsion stabilized by modified SiO(2) nanoparticles as template, PVA/SiO(2) composite microspheres with PVA hydrogel cores and shells of SiO(2) nanoparticles are successfully fabricated through freezing/thawing method. The final structure and constituents of the products are investigated through SEM, FTIR, and TGA. The PVA/SiO(2) composite microspheres obtained are applied as a drug carrier to study their controlled release behaviors and methylene blue is used as a model drug. The effect of PVA concentration, SiO(2) nanoparticle concentration, and freezing/thawing cycles on the morphology of products and release behaviors is studied. All release curves are, respectively, fitted by Monoexponential equation, Higuchi equation, Weibull equation, and Hixson-Crowell equation. Weibull equation is found to give the best fit to the release process. The fitted results prove that the drug release from the PVA/SiO(2) composite microspheres follows Fick diffusion.
authors.affiliation: a School of Chemical Engineering of Hefei University of Technology , Hefei 230009 , P.R. China.
authors.forename: Haiou
authors.initials: H
authors.lastname: Zhou
authors.forename: Tiejun
authors.initials: T
authors.lastname: Shi
authors.forename: Xun
authors.initials: X
authors.lastname: Zhou
mesh_terms: D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D005615:Freezing; D020100:Hydrogels / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D055616:Microtechnology / Q000379:methods; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012044:Regression Analysis; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D020100:Hydrogels; D014867:Water; D012822:Silicon Dioxide; D011142:Polyvinyl Alcohol; D008751:Methylene Blue