Solubility of Dexamethasone in Supercritical Carbon Dioxide with and without a Cosolvent

The solubility of dexamethasone, a synthetic glucocorticoid, in supercritical CO2 and together with 3.0 mol % ethanol as a cosolvent was measured at different temperatures (313.2, 318.2, and 323.2) K and pressures ranging from (10.0 to 25.0) MPa by a static analytical method. The obtained solubility of dexamethasone was between 1.19.10(-6) and 1.52.10(-6) in pure supercritical CO2 and between 1.97.10(-6) and 2.98.10(-6) in supercritical CO2 with a cosolvent. The experimental data in supercritical CO2 in the absence and presence of a cosolvent were correlated using four density-based semiempirical models, that is, Chrastil, Kumar and Johnston, Bartle, and Mendez-Santiago and Teja models. The results indicated that the Kumar and Johnston model gave a better correlated result than the other three with an average absolute relative deviation [AARD (%)] value lower than 2.15 %.