Volumetric and Compressibility Studies of Antimycobacterial Drug in Aqueous and Aqueous d-Glucose Solutions at Various Temperatures

Abstract

The experimental density (ρ) and speed of sound (c) data for the antimycobacterial drug ethambutol dihydrochloride (ETB·2HCl) in aqueous solution and aqueous d-glucose solutions containing fixed concentrations (0.06 and 0.1 mol·kg^–1) across the concentration range 0.01 to 0.15 mol·kg^–1 at different temperatures (293.15, 298.15, 303.15, 308.15, and 313.15 K) are reported. The experimental ρ and c data were used to compute different volumetric and compressibility parameters, including the apparent molar volume of solute (V_Φ), limiting apparent molar volume of solute (V_Φ⁰), limiting apparent molar expansivity of solute (E_Φ⁰), thermal expansion coefficient (α), isentropic compressibility of solution (κ_s), apparent molar isentropic compression of solute (K_s,Φ), limiting apparent molar isentropic compression of solute (K_s,Φ⁰), and hydration number (n_k). Additionally, the partial molar volume of transfer (Δ_trV_Φ⁰) and partial molar isentropic compression of transfer (Δ_trK_Φ⁰) parameters for the considered drug from water to aqueous d-glucose solutions were estimated. The results are interpreted in terms of molecular interactions in the studied systems.