Study of Hyoscine solubility in scCO2: Experimental measurement and thermodynamic modeling

In this research, solubility of Hyoscine, as the most well-known drugs used to relieve spasmodic abdominal pain, in supercritical carbon dioxide (scCO2) was determined at 170-410 bar for pressure and 308-348 K for tem-perature. It was found 0.79 x 10-4 to 2.83 x 10-4 of equilibrium mole fraction and 0.3 x 10-2 to 1.65 x 10-2 kg. m- 3 of equilibrium solubility. Also, obtained experimental data was correlated by common empirical models; Bartle, Chrastil, Mendez-Santiago, Kumar, and Johnston (K-J), and Teja (MST). All these models could satis-factorily correlate the experimental data with high accuracy. Among them, the MST model with the lowest AARD % value (2.942) and the highest Radj value (0.991) possesses the highest correlation precision. Furthermore, the total heat of mixing, enthalpy of vaporization, and enthalpy of solvation for the Hyoscine-scCO2 system were computed, as 20.76 kJ.mol-1, 35.71 kJ.mol-1, and-14.95 kJ.mol-1, respectively.