Bio pharmaceuticals is a major pharmaceutical science division that links the physiochemical properties of medicines in dosage form to the pharmacology, toxicology, or clinical responses observed after administration. The discipline that explains the absorption, delivery, metabolism, and removal of drugs in patients needing drug therapy is clinical pharmacokinetics. The important pharmacokinetic parameter is clearance since it defines the concentration of steady-state for a given dose rate. A proportional constant that relates the amount of drug in the body to serum concentration is the volume of delivery. The quantitative analysis of the relationship between drug exposure and pharmacological or toxicological responses is called pharmacodynamics. Interactions in pharmacodynamics are when one drug's actions are altered in the presence of other toxicokinetic, a critical step in clinical toxicology. The technique is based on precise knowledge of toxicokinetic across pharmacokinetic parameters. The relevant parameters for each Toxic that will be used in clinical practice can be determined. The relationship between dosage and reaction describes the shift in impact on an organism caused by various amounts of exposure to an organism after a certain exposure duration.