The kinetics of a pharmaceutical formulation can be determined by modelling the relation between concentration of drug in the plasma and the time elapsed since administration. The resulting concentration-time curve reflects the absorption, distribution and elimination of the drug. The simplest model that represents this,kind of data is the one compartment open model. In many situations, this serves as a convenient model for estimating the bioavailability parameters area under the concentration-time curve, time to peak concentration, and peak concentration.