Anti-inflammatory properties of a series of phenyl- and phenoxy-alkanoic acids

Abstract

Abstract Some o-benzamidophenoxyacetic, phenylalkanoic and phenoxyalkanoic acids have been synthesized. Anti-inflammatory activity was measured by the phenylbenzoquinone writhing test in mice and the rat foot oedema test. Meta- and para-substitutions in the benzamido-ring, promoting lipid solubility, enhanced the potency, whereas substitution with polar groups reduced it. Further phenylring substitution in the 2-(3,4-dichlorobenzamido)phenoxyacetic acids only slightly affected the potency. Side-chain modifications did not increase the activity on the three substituted phenoxyacetic acids chosen. Two phenylpropionic acids showed a good order of activity but the respective cinnamic acids were virtually inactive. From the investigations 2-(3,4-dichlorobenzamido)phenoxyacetic acid (SNR. 1804) was selected for further studies is now undergoing clinical evaluation.