Solubility of Lanosterol in Organic Solvents and in Water–Alcohol Mixtures at 101.8 kPa

Lanosterol is a sterol derivative whose physicochemical properties are poorly understood. Pure lanosterol (>95%) was isolated from a crude product (54.6%) by a newly developed C18 reverse-phase high-performance liquid chromatography (HPLC) method. Purity and structure were confirmed by gas chromatography–mass spectrometry (GC–MS). The melting temperature and fusion enthalpy were determined to be 408.27 K and 23.61 kJ/mol, respectively. The solubility of lanosterol was measured in methanol, ethanol, isopropanol, n-propanol, acetonitrile, acetone, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate, water, water–methanol, water–isopropanol, and water–ethanol binary systems using a static equilibrium setup from 277.09 to 338.78 K. The solid phases were characterized by X-ray diffraction and by scanning differential calorimetry. The solubility of lanosterol increases with an increase in temperature. The mole fraction of lanosterol in organic solvents has a minimum of 3.0 × 10–5 in methanol at 277.78 K and a maximum of 0.0048 in n-propanol at 318.93 K. The solubilities of lanosterol in organic solvents were correlated by the modified Apelblat equation and by the Wilson, NRTL, and UNIQUAC models. Furthermore, the binary water–alcohol systems were correlated by the Apelblat–Jouyban–Acree and the van't Hoff–Jouyban–Acree models.