Irritation potential of a new topical tretinoin formulation and a commercially-available tretinoin formulation as measured by patch testing in human subjects

Patch testing is frequently used to determine the irritation potential of topical agents. Application of test materials under occlusive conditions allows controlled evaluation and comparison of agents and is a well-established method of risk assessment.1 The Hill Top Chamber (Hill Top Research, Inc., Cincinnati, OH), which incorporates a 0.2 ml test sample, has been identified as a preferred patch testing system on the basis of a combination of test sensitivity, test material volume, and commercial availability.2 Patch testing by means of the Hill Top Chamber was used in two separate evaluations to From Hill Top Research, Inc., East Brunswick,a and the University of Medicine and Dentistry of New Jersey, Robert Woods Johnson Medical School, New Brunswick.b Reprint requests: Otto H. Mills, Jr., PhD, 223 Hwy. 18, Suite 203, East Brunswick, NJ 08816. Copyright © 1998 by the American Academy of Dermatology, Inc. 0190-9622/98/$5.00 + 0 16/0/88700 Irritation potential of a new topical tretinoin formulation and a commercially-available tretinoin formulation as measured by patch testing in human subjects