Solubilityof Dexamethasone in Supercritical CarbonDioxide with and without a Cosolvent.

Thesolubility of dexamethasone, a synthetic glucocorticoid, insupercritical CO2and together with 3.0 mol % ethanol asa 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 staticanalytical method. The obtained solubility of dexamethasone was between1.19·10–6and 1.52·10–6in pure supercritical CO2and between 1.97·10–6and 2.98·10–6in supercriticalCO2with a cosolvent. The experimental data in supercriticalCO2in the absence and presence of a cosolvent were correlatedusing four density-based semiempirical models, that is, Chrastil,Kumar and Johnston, Bartle, and Méndez-Santiago and Teja models.The results indicated that the Kumar and Johnston model gave a bettercorrelated result than the other three with an average absolute relativedeviation [AARD (%)] value lower than 2.15 %. [ABSTRACT FROM AUTHOR]