Molecular dynamics simulations of acyclovir and diazepam passive transport through a DMPC membrane. (Courtesy of Prof. A. J. Hopfinger, University of Illinois-Chicago, Chicago, IL. Copyright © 2005, The Chem21 Group, Inc., Chicago, IL. All rights reserved.). Top: Side view (A) and top view (B) of the structure for the model DMPC membrane-acycloviar complex after 200 psec of MDS. Acyclovir has low (slow) cellular permeability Bottom: Side view (A) and top view (B) of the structure for the model DMPC membrane-diazepam complex after 200 psec of MDS. Diazepam has high (rapid) cellular permeability.