Physicochemical studies of homoeopathic formulations (extremely diluted solutions) of acidum salicylicum in ethanol by using volumetric, acoustic, viscometric and refractive index measurements at 298.15, 308.15 and 318.15Â K

•The study reports physicochemical properties of extremely diluted solutions (EDS).•First physicochemical study on homoeopathic formulations of acidum salicylicum in ethanol.•The study reports new of density and ultrasonic speed data of these EDS.•The study reports new viscosity and refractive index data of these EDS.•The study elucidates the interactions/behaviour of these homoeopathic formulations.

The densities, ρ, ultrasonic speeds, u and viscosities, η and refractive indices, nD of pure ethanol, 15 samples of succussed ethanol controls, 15 formulations of acidum salicylicum in unsuccussed ethanol and 15 formulations of acidum salicylicum in succussed ethanol have been measured for potencies from 2 C to 30 C (with an interval of 2 C) at 298.15, 308.15 and 318.15 K and atmospheric pressure. From these experimental data, the isentropic compressibilities, κs, intermolecular free length, Lf, acoustic impedance, Z, relative association, RA, excess isentropic compressibility, κsE, excess intermolecular free length, LfE, excess acoustic impedance, ZE, excess viscosity, ηE and excess refractive index, nDE have been calculated. The results have been qualitatively discussed in terms of interactions/physicochemical behaviour of acidum salicylicum in these solutions. The results indicate that even in extreme dilutions the molecules of acidum salicylicum may be present in these homoeopathic formulations. Both the presence of acidum salicylicum as well as succussion phenomenon may be responsible for the variation of the physicochemical properties of these homoeopathic formulations.