Mathematical representations reported by Yin and co-workers for the Combined Nearly Ideal Binary Solvent (NIBS)/Redlich Kister model are carefully examined in regards to the model's ability to predict the solubility of trimethoprim dissolved in binary aqueous-2-propanol and aqueous-ethanol solvent mixtures. The equation coefficients reported by Yin and co-workers were found to give calculated mole fraction solubilities in the two alcohol monosolvents that exceed unity. The narrow range of solvent composition over which the authors performed solubility measurements does not enable one to derive mathematical correlations for predicting the solubility of trimethoprim in the alcohol-rich solvent composition region.