A long-acting and selective β2-adrenergic receptor agonist (Kis = 7.58 and 2,630 nM for β2- and β1-ARs, respectively); selective for β-ARs in isolated guinea pig trachea over those in atrial tissue (pD2s = 9.29 and 6.98, respectively); prevents the late asthmatic response and eosinophil and macrophage infiltration in BALF, as well as reduces bronchial reactivity in a guinea pig model of ovalbumin-induced allergic asthma at 10 μg/ml, inhaled