Some Biological Properties of Flurbiprofen, an Anti-inflammatory, Analgesic and Antipyretic Agent

2-(2-Fluoro-4-biphenyl)propionic acid (flurbiprofen) possesses peripheral analgesic, anti-inflammatory and antipyretic properties. It does not possess glucocorticoid or adrenocortical-stimulating properties. It is a highly potent agent which in acute pharmacological test systems produced a significant pharmacological effect in single oral doses varying from 0.04 to 0.47 mg/kg. The peak plasma concentrations attained after these doses were generally of the order of 1 to 3 mug/ml. Doses of 0.33 mg/kg/day, which gave peak plasma concentrations of 0.6 mug/ml, produced a significant inhibition of rat adjuvant arthritis, both developing and established. The very shallow dose-response curves for flurbiprofen compared with acetylsalicylic acid, especially in the mouse and the rat test systems, are not due to an unreliable or abnormal absorption, which suggests that in these species the mode of action of flurbiprofen is not identical with that of acetylsalicylic acid.