Apparent and partial molar properties for glycine, L-alanine and L-valine in aqueous solutions (0.0250.075) mol.kg(-1) of drug NTPH (nortriptyline hydrochloride) have been reported in the present study at intervals of 5 K from temperature 288.15 K to 308.15 K and at experimental pressure of p =0.1 MPa. Different parameters viz transfer partial molar properties, hydration numbers (n(H)), partial molar expansibility (E-empty set(0)), isobaric thermal expansion coefficient (alpha) and Hepler's constant, calculated by using the experimental data of density (rho) and ultrasonic speeds (u) predict that the solute-solvent interactions are dominating in these ternary systems. The linear variation of V-empty set(0) with the number of carbon atoms in the alkyl chain of amino acids has been utilized to calculate the contribution of the charged end groups (NH3+, COO-), (CH2) group and other alkyl chains of the amino acids to V-empty set(0). Pair and triplet interaction coefficients determined from Delta V-empty set, s(0) and Delta K-empty set(0), values using McMillan-Mayer theory indicate the dominance of pairwise interactions in the studied ternary mixtures. The hydration number (n(H)) comes out to be positive suggesting strong dehydration effect of NTPH. FTIR spectra have been recorded for the mixtures of amino acids in aqueous solutions of NTPH. The decrease in wave number of N-H stretching band also suggests the structural changes in these systems. (C) 2018 Elsevier Ltd.