Effect of 1-Butyl-3-methylimidazolium Ibuprofenate as an Active Pharmaceutical Ingredient Ionic Liquid (API-IL) on the Thermodynamic Properties of Glycine and L-Alanine in Aqueous Solutions at Different Temperatures

Recently, ionic liquids have been combined with active pharmaceutical ingredients (APIs), and a third generation of ILs has emerged (API-ILs). The effect of a novel ionic liquid containing the ibuprofenate anion as an active pharmaceutical ingredient ionic liquid (API-IL) on the thermodynamic properties of two amino acids, glycine and l-alanine, have been studied. The densities, speeds of sound, viscosities and refractive indices of glycine and l-alanine in water and in aqueous solutions of an API-IL, 1-butyl-3-methylimidazolium ibuprofenate ([BMIM][Ibu]), have been determined at temperatures 288.15-318.15 K. The measured data have been used to calculate the standard partial molar volume , partial molar volume of transfer , Hepler's constant , apparent molar isentropic compressibility , molar refraction R (D), viscosity B coefficient (B) and hydration number parameters n (H). All of these parameters are discussed in terms of the competitive interactions occurring between amino acids-[BMIM][Ibu] and amino acids-water.