Pharmacokinetics Study in Rats

Pharmacokinetic studies in Sprague–Dawley (SD) rats were conducted according to protocols approved by the Animal Care and Use Committee at Johns Hopkins University. SD rats obtained from Harlan were maintained on a 12 h light–dark cycle with ad libitum access to food and water. A test compound was administered via i.p. injection at a dose of 10 mg/kg (100% saline vehicle, 10 mL/kg volume). The rats were sacrificed at specified time points (0.25, 0.5, 1, 2, 4, and 6 h) post drug administration. For the collection of plasma and brain tissue, animals were euthanized with CO₂ and blood samples were collected in heparinized microtubes by cardiac puncture. Brains were dissected and immediately flash-frozen (−80 °C). Blood samples were spun at 2000g for 15 min, and the plasma was removed and stored at −80 °C until analysis (as described below).