Human test models for bioequivalence of topical corticosteroids: a review

It would be useful to have a safe, reliable, reproducible, and inexpensive human test model to determine the potency of topical corticosteroids and the bioequivalence of generic agents. Existing human test systems include erythema or inflammation induced by irritants or other stimuli, experimentally induced cutaneous disease-like states, and bioassays in patients with psoriasis. None of these systems is currently reliable enough to warrant general use. Among the shortcomings of existing test systems are the difficulty of producing a uniform, steroid-responsive test condition, the requirement to use occlusion in several of the systems, and the lack of agreement among the results of different tests. Despite these shortcomings, some of the tests may prove useful in comparing innovator and generic topical corticosteroids and in screening the potency of new agents.