Phenylbutazone-d9

Phenylbutazone-d9 is intended for use as an internal standard for the quantification of phenylbutazone by GC- or LC-MS. Phenylbutazone is a non-steroidal anti-inflammatory drug and an inhibitor of the peroxidase activity of COX (IC50 = ~100 μM in the presence of hydrogen peroxide) . It also inhibits prostaglandin I synthase (IC50 = ~25 μM in the presence of hydrogen peroxide) . Phenylbutazone (2 mg/kg) reduces increases in type II collagen levels in the inflamed joints of an equine model of LPS-induced acute synovitis. Formulations containing phenylbutazone have been used in the treatment of lameness in horses.