Acoustic and thermal properties of pharmaceutical racemic S(+)-R(-) ketoprofen were investigated in wide temperature range including glassy, supercooled liquid and liquid states by Brillouin scattering and temperature modulated DSC (MDSC). Sound velocity and acoustic attenuation exhibit clear changes at 265 K indicating a liquid-glass transition and show the typical structural relaxation above Tg. The high value of the fragility index m = 71 has been determined by the dispersion of the complex heat capacity. New relaxation map was suggested in combination with previous study of dielectric measurement.

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The low-temperature acoustic properties of cryoprotective ionic liquid and trehalose aqueous solutions were studied by Brillouin scattering measurement. The refractive index was measured by the prism coupling method to determine the sound velocity and attenuation accurately from the Brillouin shift and full width at half maximum (FWHM). The structural relaxation time related to liquid–glass transition was determined as a function of temperature. The fragility indices of the glass transitions were determined by temperature-modulated differential scanning calorimetry.

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