APPLICATION OF PC-SAFT AND CUBIC EQUATIONS OF STATE FOR THE CORRELATION OF SOLUBILITY OF SOME PHARMACEUTICAL AND STATIN DRUGS IN SC-CO2

In this work, the solubilities of some anti-inflammatory (nabumetone, phenylbutazone and salicylamide) and statin drugs (fluvastatin, atorvastatin, lovastatin, simvastatin and rosuvastatin) were correlated using the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) with one-parameter mixing rule and commonly used cubic equations of state Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) combining with van der Waals 1-parameter (VDW1) and van der Waals 2-parameter (VDW2) mixing rules. The experimental data for the studied compounds were taken from literature at temperature and pressure in ranges of 308-348 K and 100-360 bar, respectively. The critical properties required for the correlation with PR and SRK were estimated using Gani and Noonalol contribution group methods whereas, PC-SAFT pure-component parameters: segment number (m), segment diameter (sigma) and energy parameter (elk) have been estimated by Tihic's group contribution method for nabumetone. For phenylbutazone and salicylamide those parameters were determined using a linear correlation. For statin drugs, PC-SAFT parameters were fitted to solubility data, and binary interaction parameters (k(ij) and I-ij) were obtained by fitting the experimental data. The results were found to be in good agreement with the experimental data and showed that the PC-SAFT approach can be used to model solid-SCF equilibrium with better correlation accuracy than cubic equations of state.