| Abstract: | The pharmacokinetic profile a drug exhibits will ultimately depend on how the drug molecule interacts with the different cell membranes it encounters en route to its target site of action. Even if the drug molecule targets a soluble protein as its final site of action, there is a reasonable probability that it will interact with some cell membrane on its pathway to this biological target. In some cases, the final protein, lipid or sugar moiety target could be an integral part of the cell membrane architecture whereby the drug's interaction with the cell membrane could influence its pharmacodynamic profile as well, especially if the final site of action is an integral membrane-bound receptor protein. In either case, drug transport across a cell membrane or within the cell membrane lipid bilayer compartment can dictate partial or dominant control of the drug's bioavailability. A molecular understanding of the equilibrium membrane partition coefficient, the rates of drug partitioning into and out of a cell membrane and the equilibrium location of the drug within the cell membrane can provide critical chemical design strategies for altering overall drug bioavailability and optimal pharmacokinetics. |
