A mathematical model is described that enables calculation of drug concentration gradients within structured tissues for high affinity molecules that are taken up by cells. Access of drugs to the complete tissue mass may be prevented by high affinity binding, receptor re-binding, avid permeation into the cell and restricted diffusion (high tissue tortuosity). Varying parameters such as affinity and kinetic constants (association and dissociation rate constants) may be a strategy to manipulate affinity and penetration into structured tissues.
T P Kenakin (Fri,) studied this question.