June 1986

Development of an Objective Comedogenicity Assay

Author Affiliations

From the Department of Dermatology, University of Texas Health Science Center at Houston (Drs Tucker and Flannigan); the School of Veterinary Medicine, Texas A&M University, College Station (Dr Dunbar); and the Product Safety Department, Mary Kay Cosmetics Inc, Dallas (Dr Drotman).

Arch Dermatol. 1986;122(6):660-665. doi:10.1001/archderm.1986.01660180066016

• The rabbit ear comedogenicity assay is useful as a screening procedure for evaluating agents that come in contact with human skin. Controversy exists regarding the reliability of this assay because of differences in results from various laboratories. The subjective nature of the standard method of grading may also contribute to this variation. We use a more objective comedogenicity assay that utilizes increasing follicular orifice size on the rabbit ear as a measure of comedogenic activity. A generally linear increase in the degree of follicular orifice area was noted with several agents evaluated over a four-week application period. Further, a noninvasive Silastic elastomer mold was used to allow measurement of the same follicular orifice areas over time.

(Arch Dermatol 1986;122:660-665)