  We use a one-dimensional two layer model with a semi-permeable membrane to
study the diffusion of a therapeutic drug delivered from a drug-eluting stent
(DES). The rate of drug transfer from the stent coating to the arterial wall is
calculated by using underdamped Langevin dynamics simulations. Our results
reveal that the membrane has virtually no delay effect on the rate of delivery
from the DES. The work demonstrates the great potential of underdamped Langevin
dynamics simulations as an easy to implement, efficient, method for solving
complicated diffusion problems in systems with a spatially-dependent diffusion
coefficient.
