Experimental Measurement and Thermodynamic Modeling of Capecitabine (an Anticancer Drug) Solubility in Supercritical Carbon Dioxide in a Ternary System: Effect of Different Cosolvents

Solubility of capecitabine (CPT) in a ternary system (supercritical carbon dioxide (sc-CO 2 ) + CPT + [methanol, ethanol, and dimethyl sulfoxide (DMSO)] as cosolvents) was measured at different temperatures (308.15–348.15 K) and pressures (100–350 bar). CPT solubility in the presence of methanol, ethanol, and DMSO was in the range of 3.18 × 10–5 to 120.29 × 10–5, 0.64 × 10–5 to 71.9 × 10–5, and 0.85 × 10–5 to 94.8 × 10–5 mole fraction, respectively. A significant solubility improvement of CPT in sc-CO 2 is shown by comparison with its solubility in a binary system (sc-CO 2 + CPT) reported in the literature (Yamini et al . 2012). The solubility data were correlated by several well-known empirical models of ternary systems. Among them, the Jouyban et al . model produced the best correlation with average absolute relative deviation (AARD %) of 10.58, 9.21, and 8.92% for methanol, ethanol, and DMSO, respectively. Also, the solubility data of the methanol cosolvent were correlated by Peng–Robinson (PR-vdW2), Soave–Redlich–Kowng (SRK-vdW2), and perturbed-chain polar statistical associating fluid theory (PCP-SAFT) thermodynamic equation of state-based models. According to the mean AARD % value of PR equation of state (EoS) (20.32%) and corresponding R adj (0.9866), it could be concluded that PR EoS shows a better performance in comparison with other thermodynamic models.