The following PK parameters were calculated from the plasma TBP concentrations, blood, and plasma total radioactivity: area under the concentration-time curve from time zero to the last observed nonzero concentration, as calculated by the linear trapezoidal method (AUC0-last); area under the concentration-time curve from time zero extrapolated to infinity (AUC0-inf); percentage of AUC0-inf extrapolated, represented as (1 − AUC0-last/AUC0-inf) · 100 · (AUC%extrap); last observed (quantifiable) plasma concentration (Clast); maximum observed concentration (Cmax); time to reach Cmax (Tmax); and apparent first-order terminal elimination half-life. In addition, the ratio of AUC0-inf of the plasma TBP, relative to the AUC0-inf of the plasma total radioactivity, as well as the ratio of the AUC0-inf of the whole blood total radioactivity to the AUC0-inf of the plasma total radioactivity were determined. All of the PK evaluations were performed using Phoenix WinNonlin version 8.1 (Pharsight Corporation, Mountain View, CA, USA).
For the mass balance, the amount excreted in the urine and in the feces, the cumulative amount excreted in the urine and in the feces, the percentage excreted in the urine and in the feces, and the cumulative percentage excreted in the urine and in the feces, relative to the administered dose, were calculated.
For the mass balance, the amount excreted in the urine and in the feces, the cumulative amount excreted in the urine and in the feces, the percentage excreted in the urine and in the feces, and the cumulative percentage excreted in the urine and in the feces, relative to the administered dose, were calculated.