j. Soc. Cosmet. Chem., 37, 287-295 (July/August 1986) Abstracts The Annual Scientific Meetings and Seminars of the Society of Cosmetic Chemists are important venues for informing the participants about the state of the art and recent technical advances in the field of Cosmetic Science. To provide broader dissemination of that information, the Publi- cations Committee has decided to publish abstracts of technical presentations made at these Meetings and Seminars in the Journal.--The Editor. Society of Cosmetic Chemists Annual Scientific Meeting December 4-5, 1986 SESSION A SUNSCREENS Human sunscreen evaluation: Protection from sunburn Ward L. Billhimer, Hill Top Research Inc., P.O. Box 42501, Cincinnati, OH 45242 Sunscreens form one of the fastest growing markets in the cosmetics industry today. Sun protection factors are rapidly increasing, substantivity claims are being made by more products, and sun protec- tion is offered by a greater variety of cosmetics and personal care products than ever before. This session will review the evaluation of the performance of sunscreen products relative to the prevention of sunburn in humans. Disparity appears to exist be- tween the U.S. and German SPF values. These dif- ferences may be due to important contrasts between the two methods of indoor testing. Indoor test methods, both domestic and international, will be compared. Concerns have also been raised by the Germans and Japanese regarding the apparent lack of correlation between SPF values developed using indoor and outdoor methods. These concerns will be examined along with some of the factors which can influence the results of these tests. Sunscreens: Topical and systemic agents for protection of human skin Madhu A. Pathak, Ph.D, Harvard Medical School and Massachusetts General Hospital, Boston, MA 02114 In the prevention of sun-induced damage, three facts are important to recognize: 1) Solar UVB radi- ation (209-320 nm) is erythemogenic, carcino- genic, and induces skin aging (dermatoheliosis). 2) Long-wavelength UVA radiation (320-400 nm) is not innocuous certain wavelengths are erythemo- genic, carcinogenic, and induce DNA-thymine dimers and the generation of harmful forms of reac- tive oxygen species (e.g. 202, 07, 'OH, etc.) which damage cell membranes. 3) Sun-induced acute and chronic skin damage is directly related to the sun's UV intensity, duration of solar exposure, and is in- versely related to an individual's ability to develop melanized epidermis (tanning ability) and the ca- pacity to repair photodamaged DNA. We will re- view: 1) the methods to determine the sun protec- tion factor (SPF) value of topical sunscreens against UVB and UVA radiation 2) the technological ad- vances in the formulation of sweat- and water-resis- tant sunscreens for prolonged sunbathing 3) the SPF values of several brand-name formulations and their water-resistant properties 4) the photoprotec- tive property of melanin (suntan) and systemic sun- screens and 5) the potential undesirable side effects of topical sunscreens. Emphasis will be focused on the future needs of consumers. In vitro and animal models for sunscreen testing Homer S. Black, Ph.D., VA Medical Center, 2002 Holcomb Blvd., Bldg. 203, Houston, TX 77211 Ideally, the development and subsequent testing of potential sunscreens follows a multi-tiered schema --with in vitro methods occupying the first tier, followed by testing with animals, and finally with 287

288 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS humans. In vitro testing methods have been devel- oped to provide basic knowledge of the physico- chemical behavior of potential sunscreening agents and to avoid those instances where direct human testing has resulted in excessive costs, due to the large test population necessitated, and sometimes without the benefit of an effective, marketable product. The usual approach has been to predict the Sun Protection Factor from a variety of spectropho- tometric techniques using dilute solutions or thin films of the test agent. Utility of these techniques has been extended by direct in situ measurement of UV absorption after application of agent to mouse skin. These methods are optimally followed by an- imal tests whereby preliminary toxicity data, as well as actual ability to diminish specific biological responses to UV insult, other than erythema, can be obtained. A number of the latter tests include DNA repair capability, ornithine decarboxylase induc- tion, carcinogenesis, and manifestations of actinic aging. Statistics and factors which influence the re- sults of sunscreen testing. Robert M. Sayre, Ph.D., Schering-Plough Corpora- tion, 3030 Jackson Ave., P.O. Box 377, Memphis, TN 38151 A number of factors may affect the performance of sunscreen products on human skin. These can be generally classified as individual factors, formula at- tribute factors, instrumental factors, and test oper- ator factors. Individual factors include eye color, hair color, age, sex, skin type, and possible indi- vidual differences in the erythema effeciency spec- trum. There are other factors relative to the perfor- mance of individual products including the choice of vehicle and its cosmetic attributes. Instrumental factors which may affect the performance of a product tested include the spectral distribution of the solar simulator, its fluence, the size of the area irradiated, and the exposure increments chosen. The final set of factors are those which involve the study investigator. These include the measurement of test application area, the determination of the amount of product, and its uniform application to the skin. Also important in this category may be the administration of the exposure increments and determination of the end point. Specifically, the in- dividual factors will be examined with respect to the Schering-Plough data base of sunscreen tests. Finally, the results will be discussed relative to published studies of product efficacy and the use of alternate analysis schemes based on log-normal pop- ulation distributions and statistics. SESSION C EMULSION TECHNOLOGY Cosmetic emulsions--How to and why Abraham Seldner, Seldner Associates, 188 Grove Avenue, Princeton, NJ 08540 The most challenging product forms in cosmetic formulation are emulsions. Emulsions dominate skin care and are prominent in other applications. Pragmatic literature in emulsion formulation is scarce and has large elements of mystique that com- plicate the formulator's job in an essentially scien- tific pursuit. The author endeavors to simplify and systematize development of commercial cosmetic emulsions to yield sound, elegant, stable, and sale- able products within reasonable time frames. The role of the supplier is evaluated and the proper places of natural, synthetic, esoteric, and exotic ma- terials are assayed. The myriad of available raw ma- terials is winnowed down to a few manageable cate- gories and their roles are defined with a view toward ease of selection for product development. The art and science of formulating stable emul- sions Kenneth Klein, Van Dyk & Company, Main & Williams Sts., Belleville, NJ 07109 Formulating stable emulsions requires a solid scien- tific base augmented by a generous dose by tech- nique, sometimes referred to as art and good luck. To minimize the contribution of either (science or art) shows a naivet6 which will lead to failure at the bench. This presentation discusses: 1. The scientific basis for choosing emulsion ingredients (principally emulsifiers). 2. Processing considerations. 3. For- mulation. The last aspect (formulation) will be dis- cussed in some depth with numerous examples fo- cusing on ingredient rational. Shampoo design parameters and their effect on surfactant choice L.J. Nehmsmann, Ph.D., PPG Industries, Inc., P.O. Box 31, Barberton, OH 44203 The modern formulator has a more important and difficult task today than ever before. The market, technical, and economic demands placed upon cos- metic products are more demanding. The market fragmentation requires the formulator to produce more new formulae in less time. Fortunately, the array of surfactants available to help in this task is also larger. A review of the surfactant structures available and the characteristic properties of the various structures are given. Emphasis will be on anionics, the largest class of surfactants used in