Solvent effect, transfer property and preferential solvation of artesunate in aqueous co-solvent mixtures of some alcohols

The preferential solvation of artesunate in mixtures of ethanol (1) + water (2), methanol (1) + water (2), propylene glycol (PG, 1) + water (2) and isopropanol (1) + water (2) was investigated through the obtainable solubility data by the method of inverse Kirkwood-Buff integrals. In co-solvent-rich and intermediate compositions, artesunate was preferentially solvated by the co-solvent (methanol, ethanol or isopropanol). However, artesunate was not preferentially solvated by the solvent PG. A quantitative description of the solvent effect was obtained by modelling the change in Gibbs-free energy of solubility using linear solvation energy relationships. In addition, the transfer properties such as enthalpy, Gibbs-free energy and entropy were resulted.