title: Sol-gel Derived Warfarin - Silica Composites for Controlled Drug Release.
abstract: BACKGROUND
  Warfarin, commonly used anticoagulant in clinic, has serious shortcomings due to its unsatisfactory pharmacodynamics. One of the efficient ways for the improvement of pharmacological and consumer properties of drugs is the development of optimal drug delivery systems.
  
  
  OBJECTIVE
  The aim of this work is to synthesize novel warfarin - silica composites and to study in vitro the drug release kinetics to obtain the composites with controlled release.
  
  
  METHODS
  The composites of warfarin with unmodified (UMS) and mercaptopropyl modified silica (MPMS) were synthesized by sol-gel method. The composite formation was confirmed by FTIR spectra. The concentrations of warfarin released to media with pH 1.6, 6.8 and 7.4 were measured using UV spectroscopy. The drug release profiles from the solid composites were described by a series of kinetic models which includes zero order kinetics, first order kinetics, the modified Korsmeyer-Peppas model and Hixson-Crowell model.
  
  
  RESULTS
  The synthesized sol-gel composites have different kinetic behavior in the studied media. In contrast to the warfarin composite with unmodified silica, the drug release from the composite with mercaptopropyl modified silica follows zero order kinetics for 24 h irrespective to the release medium pH due to mixed mechanism (duffusion + degradation and/or disintegration of silica matrix).
  
  
  CONCLUSIONS
  The obtained results showed that warfarin - silica sol-gel composites have a potential application for the development of novel oral formulation of the drug with controlled delivery.
authors: Laboratory of Chemistry of Hybrid Nanomaterials and Supramolecular Systems, G.A. Krestov Institute of Solution Chemistry of Russian Academy of Sciences, 1 Akademicheskaya Str., Ivanono 153045. Russian Federation.
authors: Ekaterina S
authors: ES
authors: Dolinina
authors: Laboratory of Chemistry of Hybrid Nanomaterials and Supramolecular Systems, G.A. Krestov Institute of Solution Chemistry of Russian Academy of Sciences, 1 Akademicheskaya Str., Ivanono 153045. Russian Federation.
authors: Elena V
authors: EV
authors: Parfenyuk
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D065546:Drug Liberation; D012822:Silicon Dioxide / Q000737:chemistry*; D014859:Warfarin / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D004337:Drug Carriers; D014859:Warfarin; D012822:Silicon Dioxide
keywords: Pharmacodynamics; release kinetics; release mechanism; silica; sol-gel composite; warfarin