A high-pressure quartz crystal microbalance(QCM)apparatus was developed to investigate the absorption of carbon dioxide in two glassy polymer films—polystyrene(PS)and polyvinylpyrrolidone(PVP)at 40℃ and pressure up to 9.0 MPa.PVP was shown to have better CO2 absorption and chosen as the representative for supercritical impregnation of two model drugs—o-aminobenzoic acid and ibuprofen at 40℃ and pressure up to 8.0 MPa.It was found that the two impregnants were embedded into the polymer with a partition coefficient as high as 104 order of magnitude.Since the sub-microweighing technique established and utilized in this study was simple,convenient and accurate,it was believed that the technique could have wide and effective applications in supercritical impregnation processes.
