Calculation of solubility of methimazole, phenazopyridine and propranolol in supercritical carbon dioxide

The calculation of solid-fluid equilibrium at high pressure is important in the modeling of separation of biomolecules from food and pharmaceutical products. In this study, three equations of state along with three mixing rules are used to calculate the solubility of methimazole, phenazopyridine and propranolol, as three representative drugs, in supercritical carbon dioxide. The equations of state are: Peng–Robinson (PR), Pazuki and others and a modified PR equation. Mixing rules are VdW 1, VdW 2 and Adachi–Sugie. It is shown that Pazuki equation along with VdW 2 mixing rule is more accurate than other equations. Interaction parameters for studied systems are obtained and the percentage of average absolute relative deviation (%AARD) in calculation is displayed. Also, we use Mendez-Santiago–Teja equation to check the consistency of experimental data.