CXCR2-IN-2 is a selective, brain penetrant, and orally bioavailable CXCR2 antagonist ( IC 50 =5.2 nM/1 nM in β-arrestin assay/CXCR2 Tango assay, respectively). CXCR2-IN-2 displays ~730-fold selectivity over CXCR1 and >1900-fold selectivity over all other chemokine receptors. CXCR2-IN-2 inhibits human whole blood Gro-α induced CD11b expression with an IC 50 of 0.04 μM In Vivo CXCR2-IN-2 (compound 68) (1-10 mg/kg; p.o.; twice daily for 3 days) dose-dependently reduces neutrophil infiltration in vivo in rat and mouse air pouch models . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: 6-8 week old male C57Bl/6 mice (Air Pouch Model in Mouse) Dosage: 1, 3, and 10 mg/kg Administration: P.o.; twice daily for 3 days Result: Significantly inhibited neutrophil infiltration into mouse air pouch. Animal Model: 8-10 week old male Wistar rats (Air Pouch Model in Rat) Dosage: 1, 3, and 10 mg/kg Administration: P.o.; twice daily for 3 days Result: Inhibited neutrophil migration to air pouch in rat. Form:Solid IC50& Target:CXCR2 5.2 nM (IC 50 ) CXCR1 3.8 μM (IC 50 )