A material-conserving analytical solubility measurement technique, with in-line reversed HPLC separation protocol, was employed to measure the mole fraction solubility of lovastatin in methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, acetone, and 2-butanone between (285 and 313) K. We examine three methods for the estimation of the ideal solubility of lovastatin by using different approximations for the difference between the heat capacity of the solid and the liquid at the melting point Delta C(P) = C(P)(L) - C(P)(S). The solubility data were combined with calculated ideal solubility data to determine the activity coefficients of lovastatin which are then fitted to a van't Hoff form equation to obtain estimated values of the partial molar enthalpy of mixing, Delta(mix)H(infinity), and partial molar entropy of mixing, Delta(mix)S(infinity), respectively. Thermodynamic consistency was confirmed when Delta C(P) = C(P)(L) - C(P)(S) was used in the ideal solubility calculation.