Anti-inflammatory entrapment in polycaprolactone/silica hybrid material prepared by sol-gel route, characterization, bioactivity and in vitro release behavior

Aim: A novel organic/inorganic hybrid material, based on poly(e-caprolactone) (PCL) and silica (SiO2), were synthesized by the sol-gel method. An anti-inflammatory agent (indomethacin) was incorporated into the hybrid material to verify its local controlled drug delivery system. Methods: The structure of the interpenetrating network was investigated by Fourier transform infrared spectroscopy. The morphology of the materials was studied by scanning electron microscopy. The structure of a molecular level dispersion was disclosed by atomic force microscopy. The bioactivity of the synthesized hybrid materials was revealed by the formation of a layer of hydroxyapatite on the surface of samples soaked in a simulated body fluid (SBF). Release kinetics in SBF were subsequently investigated. The amount of drug released was detected by UV-VIS spectroscopy. Results: Pure anti-inflammatory agent exhibited linear release with time; in contrast, sol-gel silica entrapped drugs were released with a logarithmic time dependence starting with an initial burst effect followed by a gradual decrease. Conclusions: SiO2/PCL (3, 6, 9 and 12 % wt) materials, prepared via sol-gel process, are organic/inorganic hybrid and bioactive materials. All the materials showed a good release and therefore could be used as drug delivery system.