Ibuprofen is a non-steroidal anti-inflammatory drug with diverse biochemical actions, most notably inhibiting COX-1 and COX-2 (IC
50s = 2.6 and 1.53 μM, respectively).
1 It is commonly synthesized as a racemic mixture of (S) and (R) isomers (Item No. item
70280). (R)-Ibuprofen is an enantiomer that is generally not considered a COX inhibitor and is instead thought to be involved in pathways of lipid metabolism as it is incorporated into triglycerides along with fatty acids.
2 The (R) enantiomer can, however, inhibit NF-κB activation (IC
50 = 121.8 μM) in response to T-cell stimulation as well as block superoxide formation, β-glucuronidase release, and LTB
4 generation by stimulated neutrophils (IC
50 values range from 40-100 μM).
3,4 50-60% of (R)-ibuprofen is inverted to (S)-ibuprofen (Item No.
16793) in humans after oral administration.
2,5,6