<p>Selexipag is a selective non-prostanoid IP prostacyclin receptor agonist. Selexipag is a pale yellow crystalline powder that is practically insoluble in water. In the solid-state selexipag is very stable, is not hygroscopic, and is not light sensitive. Selexipag is an oral prostacyclin receptor (IP receptor) agonist that is structurally distinct from prostacyclin. Selexipag is hydrolyzed by carboxylesterase 1 to yield its active metabolite, which is approximately 37-fold as potent as selexipag. Selexipag and the active metabolite are selective for the IP receptor versus other prostanoid receptors (EP1-4, DP, FP, and TP).</p>