4.8. Pharmacokinetic Analysis in Rats
A PK study in female Wistar rats at 8–9 weeks of age was conducted at the Aurigon Toxicological Research Center (ATRC, Dunakeszi, Hungary). Up to 3 animals per cage were housed in a controlled environment at 22 ± 3 °C with a relative humidity of 50 ± 20%, 12 h light and 12 h dark. Endotoxin-free purified Tα1-PAS (3.4 mg/kg) was administered subcutaneously via a single injection into the rat dorsal area. Blood samples (100 µL) were taken from 5 animals each at various time points. Following collection in tubes containing tri-potassium ethylenediaminetetraacetic acid (K3-EDTA) (Greiner Bio-One, Frickenhausen, Germany), samples were centrifuged at room temperature for 10 min (3000× g) and the resulting plasma was stored at −15 to −30 °C. Tα1-PAS in these samples was quantified using sandwich ELISA (see below) and the data were analyzed using the Phoenix WinNonlin 6.3 software (Certara, Princeton, NJ, USA) using a one-compartment model assuming 1st order absorption and elimination.