Release Kinetics of Anti-inflammatory Drug, and Characterization and Bioactivity of SiO ₂ +PCL Hybrid Material Synthesized by Sol-gel Processing

BACKGROUND: Controlled and local drug delivery systems of anti-inflammatory agents are drawing increasing attention thanks to their possible pharmaceutical and biomedical applications. These systems have extended therapeutic effects and reduced side effects. METHODS: A single-step sol-gel process was used to prepare organic-inorganic hybrid materials based on silica (SiO2) and poly-ε-caprolactone, containing ketoprofen for controlled drug delivery applications. Fourier transform infrared spectroscopy analysis proved formation of H-bonds among the carbonyl groups of the polymer chains and Si-OH group of the inorganic matrix. X-ray diffraction analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscopy and atomic force microscope topography showed their homogeneous morphology and nanostructure nature. RESULTS: The bioactivity of the synthesized hybrid materials was shown by the formation of a layer of hydroxyapatite on the surface of samples soaked in a simulated body fluid (SBF). CONCLUSION: Release kinetics in SBF were subsequently investigated by means of UV-VIS spectroscopy. A large amount of drug release occurred during the first few hours, then a slower drug release supplied a maintenance dose until the end of the experiment.