The primary stock solutions of all compounds were prepared at 1 mg/mL in DMSO in clear salinized vials and stored at -20°C. Working standards were prepared by dilution of stock solution with 1:1 methanol:water in 1.7 mL tubes. Working stocks were prepared fresh daily and kept at -20°C.Plasma standard curves for 1 (1 -1000 ng/mL), 2 (3 -1000 ng/mL), and 3 (1 -1000 ng/mL) were prepared daily containing the compound and IS (1.25 mg/mL).