ABSTRACT
Pharmacokinetics, a branch of biopharmaceutics, is a part of the pharmaceutical sciences that describes the relationship between the processes of drug absorption, distribution, metabolism (biotransformation), and excretion (ADME) to the time course of therapeutic or adverse effects of drugs (1). Efficacy is determined by the drug concentration at the site of action, which generally is correlated with the drug concentration in the blood. The ultimate goal of pharmacokinetics is to characterize the sources of variability in the concentration-time profile which may be correlated with variability in efficacy and adverse events. Pharmacokinetics can be used to guide dosage regimen selection and thereby optimize pharmacological effects and minimize toxicological effects when a drug is administered to an individual patient. Thus, while the basic pharmacokinetic properties of a drug are identified during the earliest stage of clinical drug development, the many factors affecting the pharmacokinetics in the patient population must be identified throughout the drug development process to enable proper dose selection for individuals.
