EVALUATION OF EFFICACY AND SAFETY OF COSMETICS* By ALBERT F. GUITEP. AS Foster D. Snell, Inc., New York, N.Y. IT IS WITH considerable hesi- tation that I address this Society, because I am not a cosmetic chem- ist, and I realize full well that all of you know more about cosmetics than I do. My only excuse for accepting the kind invitation of the chairman of your Program Com- mittee is that I believe many of you may be more familiar with formu- lating cosmetics than with testing them. As one phase of our work as con- sultants, we are frequently called upon by outside firms to evaluate different products, many of which are cosmetics. The purpose of these tests is usually two-fold: first, to establish the safety of the product under conditions of use, and second, to determine .its effectiveness in accomplishing its intended objec- tive. Since it is difficult and often impossible to establish definite abso- lute standards, many of the tests, particularly the so-called perform- ance testsj are relative. In this case, comparative tests are usually run against several competitive products purchased on the open market. * Presented at the December 6, 1946, Meeting, New York City. 22 Safety tests are designed to deter- mine the safety of the product under normal' conditions of use by normal individuals. Thus, in determining the safety of a lipstick, for instance, we attempt .to establish whether or not it is apt to produce any irrita- tion when applied to the lips of a normal, average, healthy woman. We are not concerned with its pos- sible effects on a woman suffering from some particular disease, nor with any possible allergic manifes- tations. on hypersensitive individ- uals, nor with its effects on the gastro-intestinal tract if acciden tally swallowed by a child. The best method of determining the probable safety for use of most cos- metics and raw materials is the patch test. When working with new or unidentified materials, con- cerning the safety of which we can find nothing in the literature, we prefer to run some preliminary tests on rabbits, followed by a small number of humans working in our laboratory. This screening test is usually done on ten subjects and is for the purpose of discarding prod- ucts that may be strong primary irritants. Usually, these screening tests can

EVALUATION OF EFFICACY AND SAFETY OF COSMETICS 23 be dispensed with if we know the formulation of the product. The final patch test is done on at least fifty, and preferably one or two hundred subjects. The conditions of the patch test vary with the product being tested and its method of use. Some materials, such as lipsticks, are applied to the skin and left uncovered, although usually the patch is covered with an Elasto- patch, which is a strip of elastic adhesive tape, the centre of which is protected with a cell, ophane disc to prevent the adhesive material com- ing in contact with the product being tested. We ordinarily use the flexor surfaces of the arms, and although we prefer to use the lower arms be- cause they present a more rigid surface and the patches remain in place better, we are often obliged to accede to the demands of female subjects that they be patched on the upper arm. Occasionally we use the back instead of the arms, especially when a relatively large test area is desired. Some products are applied as is, others are mois- tened with water or artificial per- spiration. ,The patches are worn for periods of time ranging from several hours, in the case of certain solvents and plasticisers, to five days, in the case of textile materials. But for most cosmetics, the patches are worn for one or two days. The subjects are examined for any irritation, erythema or other derma- titis immediately after removal of the patch. The test area is then thoroughly cleaned with a suitable non-irritant solvent, followed by soap and water, and the subjects again examined after one or two hours. They are again examined the following day and at two-day intervals for one week, in order to catch any delayed reactions. If performed on a large enough number of subjects, this test will indicate whether or not the product is apt to produce an irritation on primary contact, that is whether it is a pri- mary irritant. Obviously, the greater the number of subjects patched, the greater is the accuracy and dependability of the test. If the results are questionable, or if they are apt to involve court testi- mony, they are checked by our staff physician or preferably. by a con- suiting dermatologist. Some prod- ucts are not primary irritants but they are sensitizers. In other words, a person may not react to a product when he first comes in con- tact with it, but he may thereby be sensitized to it so that subsequent exposure may produce a reaction. Although this is really an allergic reaction, the manufacturer should guard against the use of materials that may be sensitizers to even a small percentage of the population. The period during which a person is most apt to show maximum sensi- tivity is ten days to two •eeks after the original exposure. For this reason, if we wish to determine whether a product is apt to be a sensitizer, the same subjects are re- patched after ten days to two weeks with the same products in the same place as previously. The technique is exactly the same as that used in