New solubility data of Amoxapine (anti-depressant) drug in supercritical CO2: Application of cubic EoSs

Abstract

The solubility of the anti-depressant drug, Amoxapine drug, in supercritical carbon dioxide has been studied. The experiments were performed by the simple and static procedure at P = 120-300 bar and T(K) = 311, 323, 333, and 343. The drug solubilities (mole fraction) ranged from 0.44×10-6 to 7.81×10-6. The drug solubilities were modeled, first using two cubic equations of state (Peng-Robinson and Soave-Redlich-Kwong EoSs with van der Waals mixing rule) and additionally by 17 semi-empirical density-based correlations (Stahl et al., Chrastil, Kumar-Johnston, Garlapati-Madras (model I and II), Sung-Shim, del Valle and Aguilera, Adachi-Lu, Ch and Madras, Hezave and Lashkarbolooki, Mendez-Santiago-Teja, Bartle et al., Jafari Nejad et al., Hozhabr et al., Keshmiri et al., Khansary et al. and Sodeifian et al.). The results revealed that cubic EoSs and semi-empirical density-based correlations can be used to obtain satisfactory drug solubility correlations at various temperatures and pressures. Between cubic EoSs, Peng-Robinson EoS (with Akaike Information Criterion is -692.12), and among 17 density-based correlations, the Stahl et al. correlation (with AARD% = 4.16%, corresponding corrected Akaike Information Criterion is -700.98 and Radj = 0.9963) gave much better accuracy with the experimental data. The thermodynamic consistency test based on Gibbs-Durham's theory was performed by using both cubic EoSs and all experimental data were examined. Furthermore, the solvation, vaporization, and total enthalpies of Amoxapine-CO2 were calculated by Chrastil, KJ, and Bartle et al. correlations.