The evaluation of topical anti-inflammatory activity on rat ears subjected to thermal injury.

Topical anti-inflammatory activity of steroidal and non-steroidal agents was assessed on inflammation produced by heat. A burn was produced on the ears of rats and the inflammation was quantitated gravimetrically. Steroidal anti-inflammatory agents were ranked in order of decreasing activity: triamcinolone acetonide, dexamethasone, prednisolone and hydrocortisone acetate. The nonsteroidal agents phenylbutazone and indomethacin were also effective in inhibiting the inflammation. Cholesterol, a steroid devoid of anti-inflammatory activity, was inactive in this test. Hydrocortisone acetate, in particular, appears to be less effective in inhibiting this type of inflammation than inflammation produced by croton oil.