Solubilities of gimeracil (form P) in aqueous co-solvent mixtures of isopropanol, N,N-dimethylformamide (DMF), ethylene glycol (EG) and dimethylsulfoxide (DMSO) were investigated via the isothermal dissolution equilibrium method at (283.15-328.15) K under ambient pressure p = 101.2 kPa. Experimental solubility was increased with increasing temperature and mass fraction of each co-solvent. The largest solubility was found in neat co-solvents. The solids equilibrated with liquid phase were characterized by X-ray power diffraction, indicating no polymorphic transformation, solvate formation or crystal transition according to the spectral data. The Jouyban-Acree model was adopted to correlate the obtained solubility. The highest RAD and RMSD values were, respectively, 2.61 x 10(-2) and 14.96 x 10(-4). Quantitative values for the local mole fraction of DMF (EG, DMSO or isopropanol) and water around gimeracil (form P) were acquired by using the Inverse Kirkwood-Buff integrals method. The preferential solvation parameters for isopropanol were positive in the isopropanol mixtures in intermediate and isopropanol-rich compositions, which indicated that gimeracil (form P) was preferentially solvated by isopropanol. Gimeracil (form P) could act mainly as a Lewis acid interacting with proton-acceptor functional group of iso-propanol. Within the same region, gimeracil (form P) was not preferentially solvated by DMF, EG and DMSO. Furthermore, the method of linear solvation energy relationships was performed with a suitable combination of solvent polarity descriptors to explain the nature of intermolecular interactions resulting in the solubility variation in the co-solvent mixtures. (C) 2019 Elsevier Ltd.