Potent and selective CCK2 (CCK-B) receptor antagonist that displays ~ 1600-fold selectivity over CCK1 receptors (IC50 values are 1.7 and 2717 nM for CCK2 and CCK1 respectively). Has negligible affinity at a range of other binding sites (IC50 > 10 μM). Exhibits anxiolytic activity following oral administration. Purity 99%. MW (observed): 614.73