Solubility of Vitamin E Acetate in Supercritical Carbon Dioxide with Ethanol as Cosolvent

Vitamin E acetate (VEA) has been widely used as medicines, nutrients, and cosmetic additives. Solubility data are generally used to aid the design of processes to prepare products that provide the required dosage of the active compound(s). In this study, the static cloud-point method is employed to determine the solubility of VEA in supercritical carbon dioxide (scCO(2)) with ethanol (0.5, 1.0, and 2.0 mol %) as the cosol-vent at temperatures of 313.15, 318.15, 323.15, and 328.15 K, and pressures of 8-15 MPa. The results show that the solubility of VEA in scCO(2) can be remarkably enhanced by adding ethanol as the cosolvent. It could also be increased with the enhancing pressure and the decreasing temperature at the constant ethanol concentration. Furthermore, some semiempirical models including Christil-G, K-J, Bartle, MST-S, Reddy, and Perez are employed to correlate the experimental data. The average absolute relative deviations values of these models range from 2.43 to 6.86%, indicating that these models could well predict the VEA solubility data in scCO(2) + ethanol systems of this study.