• Many topical corticosteroid formulations are available as different concentrations of the steroid in a similar vehicle. We tested the existing assumption that higher concentrations give greater biologic activity. The vasoconstriction assay was used because of its known correlation with clinical activity. Statistical analyses of the different concentrations are as follows: Kenalog creams: 0.025% is equal to 0.1% is equal to 0.5%; Aristocort creams: 0.025% is equal to 0.1% is equal to 0.5%; Aristocort ointments: 0.1% is equal to 0.5%; Aristocort A creams: 0.5% is equal to 0.025% but is less than 0.1%; Hytone cream: 1.0% is equal to 2.5%; Synalar creams: 0.01% is less than 0.025% which is less than 0.2%; Topicort creams: 0.25% is equal 0.05%; and Valisone creams: 0.1% is greater than 0.01%. The assumption that increased concentration of the same steroid in the same vehicle type will give increased biologic activity is usually, but not always, incorrect for brand-name formulations now available.
(Arch Dermatol. 1989;125:1509-1511)