Solubility and preferential solvation of acetaminophen in methanol + water mixtures at 298.15 K

Abstract

The equilibrium solubility of acetaminophen in methanol + water binary mixtures at 298.15 K was determined and correlated with the Jouyban-Acree model. Preferential solvation parameters by methanol (?x1,3) were derived from their thermodynamic solution properties by means of the inverse Kirkwood-Buff integrals method. ?x1,3 values are negative in water-rich mixtures but positive in compositions from 0.32 in mole fraction of methanol to pure methanol. It is conjecturable that in the former case, the hydrophobic hydration around non-polar groups plays a relevant role in the solvation. The higher solvation by methanol in mixtures of similar cosolvent compositions and methanol-rich mixtures could be explained in terms of the higher basic behavior of this cosolvent. © 2015 Taylor & Francis.