Study of the effects of methanol, ethanol and propanol alcohols as Co-solvents on the interaction of methimazole, propranolol and phenazopyridine with carbon dioxide in supercritical conditions by molecular dynamics

Using the molecular dynamics simulation, the effect of methanol, ethanol and propanol solvents on the interaction of CO2 with methimazole, propranolol and phenazopyridine was studied under subcritical and supercritical conditions. The density of studied systems was calculated at different temperatures and pressures and relative error values were obtained. The results show good agreement with experimental data. The results revealed that methanol altered the aggregation of CO2 around phenazopyridine in supercritical conditions and increased aggregation, while for methimazole and propranolol, propanol cosolvent was more effective than other two alcohols on the aggregation of CO2 around the drug. Also, the aggregation of solvents around phenazopyridine occurs more than two other drugs. The analysis of weak interactions was performed based on Local Orbital Localization and it was determined that hydrogen interactions and steric effects of the drug ring and cage structures of CO2 play a greater role than the Van der Waals interaction.