Purity >98%. ONO-8130 is an orally bioavailable antagonist of the prostaglandin E2 (PGE2 ) receptor EP (Ki = 1.9 nM)1, It exerts a more than 1,000-fold selectivity for EP1 compared with other EP receptors. ONO-8130 suppresses pain associated with cyclophosphamide-induced cystitis in mice at 0.3-30 mg/kg. It also blocks PGE2 -induced contraction and eliminates spontaneous tone of guinea pig trachea tested in tissue organ baths.