Correlation between antiinflammatory activity and inhibition of prostaglandin biosynthesis induced by various non-steroidal antiinflammatory agents.

The effect of several non-steroidal antiinflammatory agents (some of them original from our laboratory) on prostaglandin biosynthesis in guinea pig lung (biological method) and in bovine seminal vesicles (spectrophotometric method) has been studied. When this effect is compared with the in vivo antiinflammatory activity determined in the rat carragenin foot edema and with the recommended clinical daily dose in rheumatoid arthritis, a good correlation between these properties was observed. Only mefenamic acid showed a clear discordance. The experience shows that inhibitory effect of antiinflammatory drugs on prostaglandin synthetase in vitro may be used to predict, in most cases, their antiinflammatory activity in vivo in the pharmacological screening of the new compounds. Structure-activity relationship in the UR-series is also discussed.