Thermodynamic investigation of the effect of octanol–water mutual miscibility on the partitioning and solubility of some guanine derivatives

Abstract

The effects of mutual saturation of octanol and water on solute partitioning and solubility have been examined. The partition coefficients and solubilities in octanol, water and mutually saturated octanol–water phases were determined for eight antivirus guanine derivatives. Using the solubility data, enthalpies of fusion (Δ_fusH) and melting temperatures (T_m), determined by differential scanning calorimetry (DSC), the activity coefficients of the solutes in the aqueous and organic phases were calculated. From these results the intermolecular interactions among the solute and solvent molecules in the aqueous and octanol phases were estimated. It has been shown that the mutual saturation of the octanol and aqueous phases plays an important role in the partitioning of semipolar substances, such as guanine derivatives.