Basic Pharmacokinetics

This chapter aims to introduce basic pharmacokinetic terminologies and principles underpinning a drug's life cycle in the body, from administration to elimination. A typical pharmacokinetic profile represents a drug concentration in blood over a period of time usually measured post drug administration until most of the drug is eliminated from the body. The science of biopharmaceutics is invaluable to understand the complex interplay between physicochemical properties of the drug and gastrointestinal physiology to develop innovative formulations and drug delivery systems to improve the drug absorption and bioavailability through various routes of administration. The elimination rate constant represents the proportion of the drug in the body that is eliminated in a given time. The term area under the curve refers to the total area under the drug's plasma concentration–time curve and represents total circulatory concentration of a drug over a period of time, often also referred to as total exposure.