The interactions of amino acids (histidine, valine and glycine) with drug amitriptyline as a subordinate of temperature have been perused by combination of volumetric and acoustic methods. Densities and speeds of sound of histidine, valine and glycine in aqueous solutions of amitriptyline have been measured at T = (305.15, 310.15 and 315.15) K. Apparent molar volume Vφ, apparent molar isentropic compression kφ, s, of amino acids (solute) in binary aqueous solutions of (0.0006, 0.001, 0.002 and 0.004) mol. kg−1 amitriptyline (solvent) have been designated at reported temperatures. The mentioned parameters are used to construct the solute–solvent interactions in ternary systems. The dependency of these parameters on concentration, temperature and hydrocarbon chain length of the amino acids clearly suggest the roles of amino acids in solute-solvent interactions.
