  The high frequency dynamics of Indomethacin and Celecoxib glasses has been
investigated by inelastic x-ray scattering, accessing a momentum-energy region
still unexplored in amorphous pharmaceuticals. We find evidence of phonon-like
acoustic dynamics, and determine the THz behavior of sound velocity and
acoustic attenuation. Connections with ordinary sound propagation are
discussed, along with the relation between fast and slow degrees of freedom as
represented by non-ergodicity factor and kinetic fragility, respectively.
