Solubility of capecitabine (CPT)
in a ternary system (supercritical
carbon dioxide (sc-CO2) + 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-CO2 is
shown by comparison with its solubility in a binary system (sc-CO2 + 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.