Elucidation of Molecular Interactions of Non-Steroidal Anti-Inflammatory Drug Diclofenac Potassium in Aqueous and Aqueous Urea Solutions: Acoustic and Viscometric Approach

Abstract

In this work, the physicochemical approach is proposed to reproduce the ultrasonic velocity and viscosity of diclofenac potassium over a range of temperature and concentration in aqueous and aqueous solutions of urea. Ultrasonic velocity (U) is measured at 298.15 K only. Using U values acoustic parameters like apparent molar compressibility (K_(s,ɸ)), isentropic compressibility (K_s), molar compressibility (W), acoustic impedance (Z), internal pressure (π_i), free volume (V_f), relative association (R_A), molar sound velocity (R) and free length (〖 L〗_f) have been evaluated. The relative viscosity data are analyzed at (298.15- 313.15) K using Jones-Dole relation and A_F and B_J coefficients are derived and discussed. Using the viscosity data Gibbs free energy of activation of viscous flow per mole of the solvent〖 ∆μ〗_1^(0*)And of solute 〖∆μ〗_2^(0*) were obtained. The results were discussed in terms of solute-solute and solute-solvent interactions in the studied systems.