This Demonstration shows the variation of drug concentration in human plasma of an IV bolus-administered drug over a one-hour time period. Drug-plasma concentration is dependent on the dosage (dose), volume of distribution (Vd) and clearance of the drug (CL). The volume of distribution determines the drug's plasma concentration, while clearance describes the speed in which the drug is cleared from the plasma by the body. This Demonstration might be used as a reference for medical personnel to estimate how quickly an administered drug is processed by the human body. A body mass of 70 kg is assumed.