Naproxen etemesil is a lipophilic, non-acidic, inactive proagent of naproxen that is hydrolysed to pharmacologically active Naproxen once absorbed. Naproxen is a COX-1 and COX-2 inhibitor with IC 50 s of 8.72 and 5.15 μM, respectively in cell assay. In Vitro Naproxen etemesil is a lipophilic, non-acidic, inactive prodrug of naproxen that is hydrolysed to pharmacologically active Naproxen once absorbed. Naproxen is a well known nonsteroidal anti-inflammatory drug. Naproxen is approximately equipotent inhibitor of COX-1 and COX-2 in intact cells with IC 50 s of 2.2 μg/mL and 1.3 μg/mL, respectively. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Naproxen exerts an anti-inflammatory and antifibrotic effect in mouse model of bleomycin-induced lung fibrosis. Naproxen also downregulates TGF-β levels and Smad3/4 complex formation. Naproxen is shown to inhibit the time-courses of pain, fever and PGE2 with similar potencies (IC 50 =27, 40, 13 μM). MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 8.72 μM (COX-1), 5.15 μM (COX-2)