S-892216 solid dispersion tablet was transferred to a volumetric flask, and acetonitrile/water (1:1) was added. The solution was sonicated for 15 min. The solution volume was adjusted to 50 mL by adding acetonitrile/water (1:1), and the solution was filtered through a 0.45 µm membrane filter. The absorbance of the solution at the wavelength of 247 nm was measured using a UV-HPLC system (ACQUITY UPLC H-Class, Waters Corporation, Milford, MA, USA) equipped with a reverse-phase ODS column (ACQUITY UPLC BEH C18, 1.7 µm, 2.1 × 100 mm, Waters Corporation). The column temperature was maintained at 40 °C. The mobile phase consisted of 0.1% formic acid and acetonitrile.