نبذه عن الكتاب: Among the factors that influence uptake and distribution of a drug into a tissue or organ outside the central nervous system (CNS) are blood flow, binding to proteins in blood plasma, clearance from blood, and metabolism. Since capillaries in general have numerous water-filled channels across their walls which allow ready escape of solutes up to the size of small proteins into interstitial fluid, capillary permeability is not normally a factor in limiting drug uptake. The contrary is true for brain and spinal cord. The blood–brain barrier (BBB) is frequently a rate-limiting factor in determining permeation of a drug into brain and is also an element in influencing steady state distribution. It is commonplace for pharmacologists and pharmaceutical chemists to make predictions concerning the pharmacological activity of a potential drug from its molecular structure. Those administering drugs active on cells of the CNS are generally concerned to raise and maintain an optimum concentration of the agent in the cerebral interstitial fluid where it is in contact with receptors. It would be most helpful to be able to predict both permeability at the BBB and steady state distribution of a potential neuropharmacological agent from its molecular structure.