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Updated: May 21, 2026

Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers
Published on: October 17, 2013
Does transbilayer diffusion have a role in membrane transport of drugs?
1Albany College of Pharmacy and Health Sciences, Vermont Campus, Department of Pharmaceutical Sciences, Colchester, VT 05446, USA. stefan.balaz@acphs.edu
Abstract:
The existing consensus on coexistence of transbilayer diffusion and carrier-mediated transport as two main mechanisms for drugs crossing biological membranes was recently challenged by a systems biology group. Their transporters-only hypothesis is examined in this article using published experimental evidence. The main focus is on the key claim of their hypothesis, stating that 'the drug molecules cross pure phospholipid bilayers through transient pores that cannot form in the bilayers of cell membranes, and thus transbilayer drug transport does not exist in cells'. The analysis shows that the prior consensus remains a valid scientific view of the membrane transport of drugs.
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