CP-544326 is a potent selective prostaglandin EP (2) receptor agonist which is the active acid metabolite of the prodrug PF-04217329 (Taprenepag isopropyl). CP-544326 was found to be a potent and selective EP(2) agonist (IC(50) = 10 nM; EC(50) = 2.8 nM) whose corneal permeability and ocular bioavailability are significantly increased when the compound is dosed as the isopropyl ester prodrug, PF-04217329. MW: 478.52. Purity ≥98% by HPLC