ANTI-INFLAMMATORY AND ANTIPYRETIC PROPERTIES OF N-(2,6-DICHLORO-m-TOLYL)ANTHRANILIC ACID (CI-583)

¹ Department of Pharmacology, Research Division, Parke, Davis & Co., Ann Arbor, Michigan

N-(2,6-Dichloro-m-tolyl)anthranilic acid (CI-583) is an anti-inflammatory agent with an acute oral potency 4.9 (2.4 to 10)_95% times that of indomethacin, 9.1 (4.7 to 18)_95% times that of flufenamic acid, 15 (9.6 to 23)_95% times that of phenylbutazone, 29 (17 to 50)_95% times that of mefenamic acid, 110 (61 to 190)_95% times that of aminopyrine and 150 (88 to 240)_95% times that of aspirin as determined in the UV-erythema assay in guinea pigs. In the subcutaneous cotton pellet test in rats it exhibits a significant though shallowly dose-graded antigranulation effect paralleling that of phenylbutazone at a subacute oral potency 14 (2.1 to 92)_95% times that of phenylbutazone. There was no evidence of adrenal dependence or corticoid-like effects at effective and nontoxic dose levels. The agent antagonizes yeast-induced pyresis in rats with a potency probably >10 times that of phenylbutazone by the oral route. Like flufenamic acid and phenylbutazone, and unlike mefenamic acid, it had less, if any, antinociceptive effect in quantitative tail-pinching experiments with rats than aminopyrine.