Solubility of prazosin hydrochloride (alpha blocker antihypertensive drug) in supercritical CO2: Experimental and thermodynamic modelling

Abstract

The solubility of prazosin hydrochloride (PRH, alpha-blocker antihypertensive drug) in supercritical CO2 (SC-CO2) was measured at temperatures between 308 to 338 K and pressures between 120 to 270 bar. The dissolved mole fractions of PRH ranged from 1.59×10−5 to 7.2×10−5, corresponding to solubilities of 0.003-0.022 g/L. PRH solubility data of the experiments were correlated using three models: (1) based on functional dependencies, eight established density-based models with 3–6 parameters; (2) ECM-PR EoS using a conventional mixing rule; and (3) SLE-based model. Moreover, a new modified EoS model was tested by correlating the solubility of PRH. All examined models could generate satisfactory fit to the solubility data. However, among the applied models, Sodeifian et al., model achieved superiority based on AARD criterion, while the new modified EoS model achieved superiority based on AICc criterion. Additionally, some thermodynamic properties of PRH solubility in SC-CO2 were estimated.