Diclofenac-d4 contains four deuterium atoms on the benzene ring. It is intended for use as an internal standard for the quantification of diclofenac by GC- or LC-mass spectrometry. Diclofenac is a non-selective COX inhibitor. It inhibits human COX-1 and -2 with IC50 values of 0.9-2.7 and 1.5-20 μM, respectively. Diclofenac inhibits ovine COX-1 and -2 with IC50 values of 60 and 220 nM, respectively.
