Two simple methods for the evaluation of topically active anti-inflammatory steroidal ointments.

Simple laboratory methods for quantitating the topical anti-inflammatory activity of steroidal ointments are described. One is of croton oil ear edema in rats and the other is a new method using homologous passive cutaneous anaphylaxis (PCA) in rats. In order to avoid problems such as the animals' licking and/or rubbing the ointment at the applied sites, which might result in oral uptake, each rat was housed individually and fitted with a plastic collar in the croton oil experiment. The sites of ointment application in the PCA experiment were covered with adhesive plaster. Optimal experimental conditions were as follows. In the former method, ointments were applied to the inside surface of the ear 5 min after the irritant treatment and anti-edematous activity was determined after 6 h. In the latter, ointments were applied 3 h before the antigenic challenge to the dorsal area of animals which had been passively sensitized by anti-serum, and inhibition of the increased permeability was determined 45 min after the challenge. These methods were found to be reliable with respect to sensitivity and reproducibility of data. Ointments of halcinonide, betamethasone-17-valerate, hydrocortisone-17-butyrate, fluocinonide, flumethasone-21-pivalate and beclomethasone-17,21-dipropionate were evaluated by these methods.