Measurement and thermodynamic modeling of solubility of Erlotinib hydrochloride, as an anti-cancer drug, in supercritical carbon dioxide

Low water solubility is the major problem in the formulation and development of new chemical compounds as well as their generic development. The solubility of anti-cancer drug, Erlotinib hydrochloride, in supercritical carbon dioxide was investigated for the first time at various temperatures and pressures (308-338 K and 12-30 MPa). Based on the results, the mole fraction of Erlotinib HCL varied in the range of 1.20 x 10-6-2.12 x 10-5. The correlation of solubility data was studied with Peng-Robinson's equation of state and four density-based semi-empirical models including Chrastil, Bartle et al., Me & PRIME;ndez-Santiago, Teja, Kumar-Johnston, and modified Wilson model. The accuracy of models was also explored based on statistical criteria, including average absolute relative deviation (AARD %) and adjusted correlation coefficient (Radj). The modified Wilson model exhibited superior correlation with empirical solubility data in supercritical carbon dioxide (AARD=10.45 %, Radj=0.9876).