PEG 400 solution of S-892216 anhydrous crystal was orally administered to rats (n=3) at 0.3 mg/head (weight = approximately 300 g) under a fasted condition, and then 2 mL/kg of water for injection was orally administered. Blood samples were serially collected from the jugular vein up to 24 h after dosing and centrifuged to obtain plasma samples. S-892216 amorphous solid dispersion powder was suspended in 0.5% (w/v) methylcellulose 400 solution and then orally administered to rats (n=3) at 1 mg/kg under a fasted condition. Blood samples were serially collected from the jugular vein up to 24 h after dosing and centrifuged to obtain plasma samples. The plasma concentration of S-892216 was determined using liquid chromatography with tandem mass spectrometry (LC/MS/MS). The MS systems were SCIEX Triple Quad 5500, 6500, and 6500+ (AB Sciex LLC, Framingham, MA, USA) and Xevo TQ-XS (Waters Corporation, Milford, MA, USA). After extraction with acetonitrile, samples were injected into a YMC-Triart C18 column (3 µm, 2.1 mm i.d. × 50 mm, YMC Co., Ltd., Kyoto, Japan) and eluted from the column using a gradient program (representative), with mobile phase A consisting of 0.1% (v/v) formic acid in water and mobile phase B consisting of acetonitrile, as summarized in Table . The flow rate was 0.75 mL/min. For detection using electrospray ionization in the positive ion mode, the multiple reaction monitoring precursor/product ion transition was m/z 522/368.