Correlation of elimination fraction area under the curve with total body clearance.

This study attempted to determine the area under the curve ([Formula: see text]), which corresponds to the sum of all elimination processes correlated with the total clearance value. The study attempted to determine the [Formula: see text] based on the coordinates known from classic non-compartmental pharmacokinetics for a single administration of the drug. 318 pharmacokinetics profiles were used for the analysis, obtained from 220 healthy subjects over ten studies. Pharmacokinetic calculations were performed with the use of Phoenix™ WinNonlin(®) 6.3. The leave-one-out (LOO) method was used for model cross-validation. Squared cross-validated correlation coefficient (Q (2)) parameter and the difference between Q (2) and R (2) were calculated as a measure of the internal performance and model predictive ability. A high correlation between the clearance value and [Formula: see text] was demonstrated (R (2) > 0.65). However, only in the case of four studies was it possible to validate the linear model using the leave-one-out validation procedure (R (2) > 0.86). The present study proposed a method of graphical and mathematical determination of the area under the curve for the drug elimination process after a single dose of the drug. Furthermore, the concept of calculating the statistical moments and mean elimination time (MET) only for elimination processes based on [Formula: see text] was presented. The result of this work is also a new method of determining the half-life of elimination phase based on the MET value.