title: Sol-gel silicon alkoxides-polyethylene glycol derived hybrids for drug delivery systems.
abstract: OBJECTIVE
  The potential application of hybrid systems based on silicon alkoxides and polyethylene glycol 400 as drug delivery systems was studied.
  
  
  METHODS
  They were synthesized using the sol-gel technique, using ketoprofen as a model drug. The preparation of the materials and their characterization by X-ray diffraction, infrared spectroscopy, thermogravimetric analysis are reported. Drug loading was performed during the gelation of the sols. Drug release studies were performed at pH 1.2 and 7.5 mimicking gastrointestinal environments.
  
  
  RESULTS
  Drug release was affected by the presence of polyethylene glycol in the formulation: a faster release was observed for polyethylene glycol hybrids.
  
  
  CONCLUSIONS
  The results suggest that these devices should guarantee long durability after implantation and could be suitable for sustained release: after a first period of release by diffusion, complete release will be reached by bioerosion of the matrix.
authors.affiliation: Department of General and Inorganic Chemistry, University of Parma, Parma, Italy. ilaria.alfieri@alice.it
authors.forename: Ilaria
authors.initials: I
authors.lastname: Alfieri
authors.forename: Andrea
authors.initials: A
authors.lastname: Lorenzi
authors.forename: Angelo
authors.initials: A
authors.lastname: Montenero
authors.forename: Guglielmina
authors.initials: G
authors.lastname: Gnappi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fiori
mesh_terms: D016503:Drug Delivery Systems; D005782:Gels; D007660:Ketoprofen / Q000737:chemistry; D010087:Oxides; D012825:Silicon; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D005782:Gels; D010087:Oxides; D007660:Ketoprofen; D012825:Silicon