Influence of artificial sweeteners sodium saccharin and acesulfame potassium on the hydration properties and taste behavior of the antidiabetic drug metformin

Measurements of the density, sound velocity, and viscosity of metformin hydrochloride (MetHCl) solutions in water and 0.1 mol∙kg−1 aqueous solution of sodium saccharin (Na-Sah) and acesulfame potassium (Ace-K) were carried out over the concentration range up ∼ 0.16 mol∙kg−1 to MetHCl at nine temperatures T = (278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15) K. Several physicochemical properties of these systems were determined from the experimental data, including apparent molar volumes, apparent molar volumes at infinite dilution, finite apparent molar volumes of transfer, apparent specific volumes at infinite dilution, apparent molar isentropic compressibility at infinite dilution, hydration numbers, viscosity B coefficients, and thermodynamic parameters of viscous flow. The results were further discussed in terms of solute–solvent and solute–solute interactions to enlighten the interactions of metformin with artificial sweeteners in water and the possibility that artificial sweeteners mask the bitter taste of metformin.