Experimental measurement and correlation of solubility of ethosuximide in supercritical carbon dioxide

Ethosuximide is a succinimide anticonvulsant active pharmaceutical ingredient. A simple static method by determining the cloud point pressure is employed to measure the solubility of ethosuximide in supercritical carbon dioxide (SC-CO 2 ) at various temperatures T /K = (313.15, 318.15, 323.15 and 328.15) and in pressures P/ MPa = (9–15). The experimental solubility of ethosuximide in SC-CO 2 is found to be between 3.45E-03 and 8.71E-03 in terms of mole fraction under the experimental conditions. The measured solubility data are successfully correlated by four semi-empirical models including Chrastil, Bartle et al., Kumar and Johnston (K-J) and Mendez-Santiago-Teja (MST). The correlation results show good agreement with the experimental data. The average absolute relative deviation (AARD) between the measured values and the calculated ones are 2.64%, 2.98%, 3.02% and 3.25% for Chrastil, Bartle, K-J and MST respectively. The results of this study provide the effective fundamental for the probable processes based on SC-CO 2 .