Prediction of solubility of sunitinib malate (an anti-cancer drug) in supercritical carbon dioxide (SC–CO2): Experimental correlations and thermodynamic modeling

Abstract

The solubility of sunitinib malate, an anti-cancer medicine, in supercritical carbon dioxide (SC–CO2) was measured for the first time. Under the applied conditions in terms of pressure (120–270 bar) and temperature (308–338 K), the numbers of dissolved mole fractions were obtained in the range of 0.5 × 10−5 to 8.56 × 10−5. For correlating the solubility data of the drug, two sets of methods including (1) three equations of states (EoSs), namely Peng-Robinson (PR), Soave–Redlich–Kwong (SRK), and Patel-Teja with vdW2 and Wong-Sandler mixing rules (with NRTL activity model), and (2) eight semi-empirical density-based models were selected. According to the results, among the other EoS-based models, the PT-WS-NRTL EoS could better estimate the actual values of the SC-CO2 solubility of sunitinib malate at 308 and 318 K. Also, by comparing the obtained results, it could be concluded that the three EoSs with the two mixing rules failed to properly correlate the solubility data of the drug at higher temperatures (328 and 338 K). Among the semi-empirical models, the Sodeifian et al. model produced the best correlation with AARD%, Radj and F-values of 12.16%, 0.9899 and 383.64, respectively.