Anti-inflammatory, analgesic and other related actions of 4'-chloro-5-methoxy-3-biphenylylacetic acid (DKA-9).

4'-Chloro-5-methoxy-3-biphenylylacetic acid (DKA-9) is a novel phenylacetic acid derivative with marked anti-inflammatory, analgesic and antipyretic activities. DKA-9 was approximately 2 times and 25 times more effective than ibuprofen in inhibiting carrageenin-induced paw edema and adjuvant-induced arthritis, respectively, in rats. The anti-inflammatory effect of DKA-9 was observed also in adrenalectomized rats. In the Randall-Selitto test in rats, DKA-9 was about 2 times more potent than ibuprofen and equipotent to indometacin. In lowering brewer's yeast-induced fever in rats, DKA-9 was almost 1/2 times more effective than ibuprofen. Considering from therapeutic index (ED50 in ulcerogenic effect/ED50 in carrageenin-induced edema), DKA-9 was found to be much superior to indometacin or ibuprofen.