Application of in Vivo Data on Chemical—Biological Interactions

Abstract

Chemical-biological (CB) interactions are governed by both the structure of the chemical and the properties of the biological system. The ability of a drug or chemical to be absorbed from the lung, skin, or gastrointestinal tract and to enter the body is a CB interaction. Unless the chemical structure is fat-soluble enough to dissolve in the lipoprotein membrane, or small enough to pass through pores, or it mimics an endogenous substance that is actively transported, the chemical cannot move across membranes or skin. Ultimately, for a chemical to exert an effect it must be absorbed and enter the blood. Once in the blood, a chemical’s further disposition is governed by its pharmacokinetic characteristics, i.e., its distribution and elimination from body compartments.