Determination of micelle formation of ketorolac tromethamine in aqueous media by acoustic measurements

Density and speed of sound of ketorolac tromethamine in aqueous solutions have been measured as a function of concentration at atmospheric pressure and in the temperature range from 293.15 to 313.15 K. Apparent molar volumes, apparent isentropic compressibility and isentropic compressibility values have also been calculated from the experimental density and speed of sound data. Partial molar volume and partial molar isentropic compressibility are obtained from fitting procedures the data on apparent molar volume, Vϕ, and apparent isentropic compressibility, Kϕ(S). Partial molar volume, Vϕ0, and partial molar isentropic compressibility, kϕ(S)0, are informative thermodynamic characteristics that reflect solute hydration. The critical micelle concentration (CMC) was determined from speed of sound data by an analytical method based on the Phillips definition of the CMC. Using these results, it was possible to establish the solvent–drug interactions.

Graphical abstractValue of critical micelle concentration (CMC) were detected by speed of sound and determined by an analytical method based on the Phillips definition of the CMC.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The aim of this study was to investigate the aggregation behaviour of KT. ► Influence of KT concentration and temperature upon volumetric properties was studied. ► CMC of KT aqueous solution was determined by using speeds of sound measurements.