Pharmacokinetic Data Analysis and Reporting

Non-Compartmental Analysis and Key Parameters Following generation of validated concentration-time data, non-compartmental analysis is typically performed...

Non-Compartmental Analysis and Key Parameters

Following generation of validated concentration-time data, non-compartmental analysis is typically performed to derive the pharmacokinetic parameters that characterise drug exposure and disposition without imposing an assumed compartmental model structure. Maximum observed plasma concentration and the corresponding time of its occurrence are read directly from the concentration-time profile and respectively reflect the extent and rate of drug absorption. The area under the concentration-time curve, calculated by the trapezoidal rule up to the last measurable concentration and extrapolated to infinity using the terminal elimination rate constant, quantifies total systemic drug exposure and forms the primary basis for bioequivalence assessment. The terminal elimination rate constant, derived from the slope of the log-linear terminal phase of the concentration-time curve, yields the elimination half-life, which describes the time required for plasma concentration to decline by one half and informs dosing interval selection. Volume of distribution and clearance respectively characterise the extent of drug distribution into body tissues and the rate of its elimination from the systemic circulation, while absolute or relative bioavailability quantifies the fraction of an administered dose that reaches the systemic circulation intact.