J. Soc. Cosmet. Chem., 31,213-218 (July/August 1980) Clinical aspects of safety testing cosmetic products in the nineteen-eighties PAUL B. KOEHLER, M.D., Chesebrough-Pond's Inc., Trumbull Industrial Park, Trumbull, CT 06611. Received January 11, 1980. Presented at the Society of Cosmetic Chemists Annual Scientific Meeting, New York, New York, December 1979. Synopsis In the 1980s more reliance will be placed on human testing for establishing the SAFETY of NEW COSMETIC PRODUCTS. Additionally, consumer groups and regulatory agencies will impose greater responsibilities on manufacturers to assure the safety of newly marketed products. The end result will be more testing and greater expenditures of time and monies. The standard battery of tests will still include the twenty-one-day cumulative irritancy test, the Maximization or Draize-Shelanski Tests for sensitization potential and, on appropriate products, photopatch testing for phototoxic or photoallergic potential. Before entry in the marketplace, HUMAN USAGE TESTING will encompass longer time periods than previously used. Certain products will undergo exaggerated use studies or be placed with particular population groups (for instance, atopics) for assessing subjective irritation such as burning or stinging. Stricter attention, too, will be paid to the possibility of percutaneous absorption of cosmetic ingredients from different vehicles. OVERVIEW In my opinion, the 1980's will see a greater demand for, and reliance on, human testing, even though animal testing, despite adverse publicity, will continue to be used. The "Friends of Animals" are busy and actively promoting, not only in the United States but also abroad. In the United Kingdom, the Committee for the Reform of Animal Experimentation wants LD50 testing in animals abolished or phased out (1). The group claims that the use of the LD50 to get precise estimates is neither necessary nor helpful in evaluating human safety. The question is asked, "Why not give the animals a dose equivalent to the highest dose that a human is likely to ingest, a so-called 'limit test' ?" A rough estimate of the number of animals involved in LD50 tests in the United Kingdom in 1977 was 229,500--87% of this number were rats and mice, and most of the rest were fish and birds, as part of ecological testing programs. The perennial search for the animal whose skin mimics that of humans will continue even though the baby Yorkshire pig is currently being proclaimed as the animal species of choice. Nevertheless, between animal and human skin there will remain the 213

214 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS structural and histological differences, the problems of transport across the skin and metabolism within the skin, and the unique differences of the human in response to irritation and sensitization. These differences will continue to plague us in our efforts to extrapolate animal skin test data to the most likely effects in man. We are all familiar with words descriptive of our economy, such as "depression," "recession," "gold fever" and "inflation." Inflation, however, is a truism that will continue to stalk us, profoundly accelerating the cost of our safety testing, particularly when it relates to human panelists. Gasoline shortages and prices have created a very real problem involving the transportation costs of panelists getting to and from a testing facility. This suggests that the testing laboratory which is located within a convenient and economical mass-transportation system, or one which is located near a large population of young people, will grow and survive the torments of inflation. In the future, consumer groups and regulatory agencies will continue to impose greater responsibilities on manufacturers of cosmetics, toiletries, and topical drugs to assure the safety of newly marketed products. The end results for the manufacturer will be more and more testing, with very specific protocols for meaningful studies, as well as greater expenditures of time and monies. The domino effect, culminating in a higher cost of final product to the consumer, can only fan the fires of inflation. HUMAN SAFETY TESTS THAT WILL PERSEVERE SKIN IRRITATION During the past decade, the twenty-one-day cumulative irritancy test has been used very successfully for assessing and ranking the mildly irritating potential of new products (2,3). It will continue to be used. Low-irritancy and high-irritancy controls-- products that have been found repeatedly to give low and high irritation scores, respectively--should always be included in this test. It is also important that these controls be your own products, whose formulations are known. Admittedly, patches can shift or fold on panelists' backs, or a panel can be comprised of one or two individuals with jittery skin, akin to those subjects with twitchy lungs or hyper-irritable airways so conducive to bronchospasm, or high temperature and humidity can dilute the test product under the occlusive patch or provoke an annoying and confusing tape dermatitis. Nevertheless, reliable testing facilities, with well-trained personnel augmented by careful and experienced monitors, can make the twenty- one-day cumulative irritancy test a useful and reproducible procedure. There are researchers and dermatologists, however, that regard the patch test, wherein a product is presented to the skin under a dressing, as an archaic procedure, deserving a decent burial. The Duhring Chamber-Scarification Test has received notoriety as a means of circumventing many of the disadvantages of patch testing (4). Certainly, this type of test is capable of detecting subtle differences in irritation potential of toilet soaps (5). Unfortunately, the procedure is profoundly influenced by meteorological conditions, and testing, at least in the Northeast, is best performed only in the winter months. Immediate and temporary burning or stinging, purely subjective responses without the subsequent development of redness, scaling or edema, can create a perplexing and annoying problem. This is particularly true if you happen to be the individual charged