Structure-making behaviour of L-arginine in aqueous solution of drug ketorolac tromethamine: volumetric, compressibility and viscometric studies

In this work, density rho, speed of sound u and viscosity eta, were measured for L-arginine in aqueous ketorolac tromethamine solutions at various temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and at atmospheric pressure. Apparent molar volume V-phi, limiting apparent molar volume V degrees(phi), limiting apparent molar volume of transfer V degrees(phi,tr), limiting molar expansivity E degrees(phi), Hepler's constant and hydration number n(H) were obtained using density data. Apparent molar isentropic compression K-phi,K-S, limiting apparent molar isentropic compression K degrees(phi,S), limiting apparent molar isentropic compression of transfer K degrees(phi,S,tr) and hydration number n(H) were obtained using speed of sound data. Jones-Dole coefficient-B B, viscosity B-coefficients of transfer B-tr, variation of B with temperature (), free energy of activation of viscous flow per mole of solvent Delta mu degrees(#)(2) and per mole of solute Delta mu degrees(#)(1) were obtained from viscosity data. The obtained results are discussed in terms of solute-solvent interactions in these systems.