Acoustic and thermal anomalies in a liquid–glass transition of racemic S(+)–R(−) ketoprofen

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. Sound velocity and acoustic attenuation exhibited clear changes at 265 K indicating a liquid–glass transition and showed the typical structural relaxation above Tg. The high value of the fragility index m = 71 was determined by the dispersion of the complex heat capacity. New relaxation map was suggested in combination with previous study of dielectric measurement.