Suprofen, a potent antagonist of sodium urate crystal-induced arthritis in dogs.

A standardized sodium urate-induced arthritis test in dogs is described in detail. A microcrystalline suspension of 20 mg/ml in 0.9% NaCl was injected into one of the stifle joints in a volume of 0.5 ml and motor impairment of the dogs was scored every 30 min over a period of 8 h. A direct quantitative comparison was made of the anti-arthritic activity of acetyl-salicylic acid, phenylbutazone, indometacin and alpha-methyl-4-(2-thienylcarbonyl)benzeneacetic acid (suprofen). All compounds were given by oral gavage immediately after the sodium urate injection. Among the compounds studied suprofen was the most potent antagonist of sodium urate-induced arthritis in dogs. Comparing the ED50 values suprofen was about 4 times as potent as indometacin, 9 times as potent as phenylbutazone and 60 times as potent as acetyl-salicylic acid.