Membrane
permeability of drug molecules plays a significant role
in the development of new therapeutic agents. Accordingly, methods
to predict the passive permeability of drug candidates during a medicinal
chemistry campaign offer the potential to accelerate the drug design
process. In this work, we combine the physics-based site identification
by ligand competitive saturation (SILCS) method and data-driven artificial
intelligence (AI) to create a high-throughput predictive model for
the passive permeability of druglike molecules. In this study, we
present a comparative analysis of four regression models to predict
membrane permeabilities of small druglike molecules; of the tested
models, Random Forest was the most predictive yielding an R
2 of 0.81 for the independent data set. The
input feature vector used to train the developed prediction model
includes absolute free energy profiles of ligands through a POPC-cholesterol
bilayer based on ligand grid free energy (LGFE) profiles obtained
from the SILCS approach. The use of the membrane free energy profiles
from SILCS offers information on the physical forces contributing
to ligand permeability, while the use of AI yields a more predictive
model trained on experimental PAMPA permeability data for a collection
of 229 molecules. This combination allows for rapid estimations of
ligand permeability at a level of accuracy beyond currently available
predictive models while offering insights into the contributions of
the functional groups in the ligands to the permeability barrier,
thereby offering quantitative information to facilitate rational ligand
design.