Volumetric, acoustic and viscometric studies of l-histidine in aqueous solutions of non-steroid anti-inflammatory drug ketorolac tromethamine at different temperatures

Abstract

In this investigation density, speed of sound and viscosity of l-histidine (0.015–0.135) molkg−1 in aqueous ketorolac tromethamine solutions (0.1–0.7) molkg−1 at various temperatures (293.15, 298.15, 303.15, 308.15 and 308.15) K and at atmospheric pressure were studied. These data were further used to calculate apparent molar volume, VΦ, limiting apparent molar volume, V°Φ, limiting apparent molar volume of transfer, V°Φ,tr, apparent molar isentropic compression, KΦ,S, limiting molar isentropic compression, K°Φ,S, limiting apparent molar isentropic compression of transfer, K°Φ,S,tr, hydration number, nH, Jones-Dole coefficient-B, B, viscosity B-coefficients of transfer, Btr and the activation parameters, ∆μ°#1 and ∆μ°#2. The results obtained from all these thermodynamic parameters were discussed in terms of solute-solute interactions and solute-solvent interactions on the basis of co-sphere overlap model and the transition state theory.