Supercritical CO_2-assisted preparation of ibuprofen-loaded PEG-PVP complexes: Comparison with conventional processing methods

摘要

Transdermal drug-delivery systems based on the interpolymer complexation (IPC) between poly(ethylene glycol) (PEG) and poly(vinylpyrrolidone) (PVP) has so far only been prepared in aqueous or solvent medium. Supercritical CO_2 as alternative process medium is attractive since its "soft" process environment could allow a greater number of drugs to be incorporated in such IPC's for transdermal delivery. The aim of this study was to first determine if supercritical CO_2 can facilitate the formation of stoichiometric PEG-PVP interpolymer complexes. Then, comparisons between ibuprofen-loaded PEG-PVP complexes prepared via conventional solvent casting method and in supercritical CO_2 were made. Finally, the effects of supercritical CO_2 process conditions on the characteristics of ibuprofen-loaded PEG-PVP complexes were studied. Analytical techniques used were: differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray diffraction (XRD), Overall it was shown that ibuprofen-loaded PEG-PVP complexes can be prepared from supercritical CO_2 processing showing similar characteristics to such complexes prepared from solvent casting.