Density, ultrasonic velocity and viscosity measurements of four pharmacologically significant drugs in methanol at 25°C

• Published in: Journal of molecular liquids Vol. 75; no. 1; pp. 33 - 43
• Main Authors: Jahagirdar, D.V., Arbad, B.R., Mirgane, S.R., Lande, M.K., Shankarwar, A.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1998
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/S0167-7322(97)00021-4

Density, ultrasonic velocity and viscosity of four pharmaceutically significant drugs were measured in methanol at 25°C. The apparent molar volume (∅ v), apparent molar compressibility (∅ K) and the viscosity B-coefficient were calculated from the experimental data. The variation of ∅ v and ∅ K with a drug concentration is linear. Values of ∅ vo and ∅ Ko are used to understand solute-solvent interactions. ∅ vo and B-coefficient show wide divergence depending on the size, shape and structure of a drug, while ∅ Ko are close to each other for all the four molecules. The first two parameters show differential solute-solvent interactions, while ∅ Ko show that the drugs compress the solvent to the same extent. This observation is supported by B/∅ vo and solvation numbers (S n) of the drugs.