  We propose a simple approach to investigate the structural relaxation time
and glass transition of amorphous drugs. Amorphous materials are modeled as a
set of equal sized hard spheres. The structural relaxation time over many
decades in hard sphere fluids is theoretically calculated using the Elastically
Collective Nonlinear Langevin Equation theory associated with Kramer's theory.
Then, a new thermal mapping from a real material to an effective hard sphere
fluid provides temperature-dependent relaxation time, which can compare to
experiments. Numerical results quantitatively agree with previous experiments
for pharmaceutical binary mixtures having different weight ratios. We carry out
experiments to test our calculations for an ezetimibe-simvastatin-Kollidon VA64
mixture. Our approach would provide a simple but comprehensive description of
glassy dynamics in amorphous composites.
