Study of solvation behaviour and interactions of drug betaine hydrochloride in aqueous-D-xylose/L-arabinose solutions at different temperatures by using volumetric, acoustic and viscometric methods

Abstract

The densities, ρ, ultrasonic speeds, u and viscosities, η of the drug betaine hydrochloride in water and in aqueous−D-xylose/L-arabinose (5 wt% and 10 wt% D-xylose/L-arabinose in water) solvents at various temperatures (293.15–318.15) K and at atmospheric pressure of 101 kPa have been measured by using digital vibrating tube density and sound analyser and micro viscometer. The experimental data have been used to evaluate the apparent molar volumes, Vϕ, limiting apparent molar volumes, Vϕo, apparent molar compressibilities, Ks,ϕ, limiting apparent molar compressibilities, Ks,ϕo, apparent specific volume, Vϕ,sp, transfer volumes, Vϕ,tro and transfer compressibilities, Ks,ϕ,tro. The viscosity A and B coefficients, Gibbs free energies of activation of viscous flow per mole of solvent, Δμ1o# and of solute, Δμ2o#, enthalpies, ΔHo# and entropies, ΔSo# of viscous flow, were obtained using the viscosity data. The effect of concentration, temperature, taste behaviour and solute structure were discussed in terms of solute–solvent and solute–solute interactions prevailing in these systems.