[Comparative evaluation of the potencies of external corticoids with various test methods]

In order to classify the new topical preparations amcinonide cream and prednicarbate cream according to the order of potency laid down by the EEC commission, we performed a number of test series in healthy young persons. Betamethasone valerate cream, clobestasol propionate cream, flumethasone pivalate cream, hydrocortisone butyrate cream, and hydrocortisone cream were comparatively tested. In addition, we included a cream base without any active substances in every test series. By means of the vasoconstriction test we were able to establish the order of rank according to potency starting from clobetasol propionate to hydrocortisone. Thus amcinonide was classified as a very strong corticoid preparation, whereas prednicarbate turned out to be moderately strong. The differences in potency between clobetasol propionate and amcinonide on the one hand and prednicarbate, flumethasone pivalate and hydrocortisone on the other hand were definitely proved (p less than 0.01). Further comparative studies were conducted on the basis of the kerosene test, the sorbic acid test, the prick test with codeine, and the anthralin inflammatory test. Moreover, the preparations underwent the formic acid test. The rank orders displayed in the individual tests largely agreed with that obtained by the vasoconstriction test. The exact differences in potency, however, were not as easy to define with the inflammatory tests. Thus the vasoconstriction test must still be considered an excellent screening technique with regard to the selection of corticoid preparations. Subsequently, these preparations should be investigated by means of clinical tests according to their ascertained potencies.