Ultrasonic Velocity Studies of Drug Parvon-spas in Mixed Alcohol–Water Solvent Systems at 25°C

Ultrasonic velocities and densities of the drug Parvon-spas in binary mixtures of water with methanol (MeOH), ethanol (EtOH), and propan-1-ol (1-PrOH) have been measured over the complete solvent composition range at 10 mol% iIntervals at 25◦C. Various acoustic parameters such as the acoustic impedance (Z), adiabatic compressibility (β), iIntermolecular free length (Lf ), relative association (R.A.), molar volume (Vm), and molar sound velocity (Rm) have been calculated. In addition, excess functions, i.e., excess adiabatic compressibility (βE), excess iIntermolecular free length (LEf ), excess molar volume (V E), excess ultrasonic velocity (UE), and excess acoustic impedance (ZE) for these three solvent mixtures in the absence and presence of the drug have been calculated. A different behavior of these parameters in these alcohol systems has been discussed in terms of the length of the alcohol molecule, the molecular volume, as well as iInter/intramolecular iInteractions of these molecules.