Analgesic and anti-inflammatory effects of some benzanilides

Analgesic and anti-inflammatory effects of N-(p-ethoxyphenyl)-2,6-dihydroxybenzamide (1), N-(p-ethoxyphenyl)-2,6-diacetoxybenzamide (2), N-(p-ethoxyphenyl)-2,5-dihydroxybenzamide (3), and N-(p-ethoxyphenyl)-2,5-diacetoxybenzamide (4) have been investigated in mice and rats. The analgesic effect of 2 on acetic acid-induced writhing was found to be stronger than that of aspirin, whereas that of 1, 3, and 4 was weaker than that of aspirin. In inflammatory studies, 1-4 showed inhibition of formaldehyde-induced paw swelling (edema). The effects of 1-3 were more potent than that of aspirin, 1 being the most potent. The potency of 4 was almost equal to that of aspirin.