Electronic Properties of Drug Molecules

Indirect electronic effects occur over a longer range than direct effects, requiring no orbital overlap. Electrostatic ionic interactions fall partly within this category, since the 

Dmg transport during the pharmacokinetic phase represents a compromise between the increased solubility of the ionized form of a drug and the increased ability of the non-ionized form to penetrate the lipid bilayer of cell membranes. A drug must cross many lipid barriers as it travels to the receptor that is its site of action. Yet cell membranes 

More recently, a variety of other methods has been developed to describe the electronic distribution properties of drug molecules. The electron distribution in a molecule can be estimated or determined by experimental methods such as dipole-moment measurements, NMR methods, or X-ray diffraction. The latter method provides very accurate electron-density maps, but only of molecules in the solid state it cannot be used to provide maps of the nonequilibrium conformers of a molecule in a physiological solution. 

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