and water (1:1). First, 10 mL of the sample was collected at predefined time points and filtered through a 0.45 µm filter. Then, the absorbance of the filtrate at the wavelength of 299 nm was measured using a UV-HPLC system (ACQUITY UPLC H-Class, Waters Corporation) equipped with a reverse-phase ODS column (X Bridge C18, 3.5 µm, 4.6 mm × 150 mm, Waters Corporation). The column temperature was maintained at 40 °C, and the mobile phase (0.1% formic acid/acetonitrile, 53/47, v/v) was delivered at the flow rate of 1.0 mL/min. The concentration of the sample solution was determined by comparing the area of the S-892216 peak in the sample solution to that of a standard solution with a known concentration.