2.6. Blood and Saliva Sampling
To ensure the validity of the time-dependent concentration determinations, blood and saliva samples were taken with a maximum time deviation of 5% of the planned time intervals. On days 1, 5, 15, and 19, blood samples were taken using a peripheral venous indwelling catheter placed in the crook of the subject’s elbow. At the end of each study day, the catheter was removed. On the shorter measurement days (days 2, 3, 4, 16, 17, and 18), blood samples were taken using a disposable cannula (butterfly). At any time point scheduled, 9 mL of peripheral blood was taken in an EDTA K3 MonovetteAfter collection, blood samples were centrifuged at 4 °C and 3000× The saliva samples were placed in appropriate microtubes by the study participants immediately after the respective blood sampling and frozen at −80 °C.