(R)-Ibuprofen

(R)-Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) and an isomer of (+-)-ibuprofen (Item No. 70280).{6935} Unlike (S)-ibuprofen (Item No. 16793), (R)-ibuprofen does not inhibit COX-1 or COX-2 in vitro (IC50s = 360 and 15.6 µM, respectively) but is converted to the active (S)-enantiomer in vivo.{27418,66347} It inhibits NF-kB transactivation in a reporter assay using Jurkat T cells (IC50 = 121.8 µM).{6935} (R)-Ibuprofen decreases superoxide formation and B-glucuronidase release induced by N-formyl-Met-Leu-Phe (fMLP; Item No. 21495), as well as leukotriene B4 (LTB4; Item No. 20110) formation induced by calcimycin (A23187; Item No. 11016), in human polymorphonuclear (PMN) cells (IC50s = 0.43, 0.58, and 0.22 µM, respectively).{27418} Formulations containing (+-)-ibuprofen have been used in the treatment of fever and mild-to-severe pain.