CEMENTING SUBSTANCE OF HUMAN HORNY LAYERS 117 proved that similar preparations had no advantage whatever over a placebo (13). To the cosmetic chemist the discovery of new components t•as great significance. Cosmetic chemistry's main task is the physical and chemical modification of horny structures to enhance beauty. In this area cosmetic science has made outstanding contributions. Recently, controversy arose about the proper role and function of cos- roetic chemistry (14). By incorporating drugs and hormones into cosmetic preparations, cosmetic chemists have "penetrated the barrier" and invaded the field of dermatology. The implication is that the main areas of funda- mental interest to cosmetic chemistry have been exhausted. Present re- search trends in dermatology do not warrant such a gloomy view. In a manner of speaking, cosmetic chemists have barely begun to scratch the surface. Pertinent to such a more optimistic view are common cosmetic problems, such as emolliency and "moisturizing" and their relation to the presented material. To date, it is impossible to explain emolliency in accurate physical or chemical terms a probable definition might be a softening of the horny layer by differential adsorption of fatty substances. In such a process the lipoprotein of horny layers may play a major role, by mixing with the topically administered lipids. Yet, while this Society has sponsored a symposium on absorption through the skin, with the exception of a single study (15), there has been no systematic study of adsorption of fatty sub- stances into the horny layer. Closely related is the concept of "moisturizing," the unsolved problem of the hygroscopic components of the horny layer. In Blank's classical ex- periments (16), pyridine and other polar solvents were the most effective in paving the way for the removal of the hygroscopic components by water. In our experience, these solvents also dissolve the lipoprotein of the horny layer. It is therefore likely that it is the lipoprotein which protects the hygroscopic components against the leaching effect of water. These are two examples of time-honored concepts in cosmetic chemistry, inviting a fresh approach. Such a new outlook can be gained by basic re- search only. The responsibility for such research rests with cosmetic chemists. Cosmetic science has been for long a field in its own right and need not be in conflict with dermatology. SUMMARY From normal and pathologic human horny layers, which have been ex- haustively pretreated with ether, it is possible to extract with alcohol a fatty material. Chemical analyses of this substance suggest that it is a lipoglycoprotein containing phosphorus and amino sugar. The material is soluble in many polar solvents. Quantitative and qualitative differences

118 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS exist between the lipoprotein of normal and pathologic horny layers. The theory is advanced that the cementing substance of human horny layers is a complex molecule, containing mucoproteins and phospholipids. Various solvents extract different fractions of this material. After its ex- haustive extraction, the flow rates of liquids through pulverized pathologic scales are increased appreciably. These findings may be important in understanding emolliency and hygroscopicity of the stratum corneum. Acknowledgment: The help of Dr. Elizabeth C. J. Esoda who took part in every phase of this research and the assistance and cooperation of Chesebrough-Pond's Inc., are gratefully acknowledged. (Received December 2, 1961) REFERENCES (1) Flesch, P., Roe, D. A., and Esoda, E. C. J., •7. Invest. Dermatol., 34, 17 (1960). (2) Flesch, P., and Esoda, E. C. J., Ibid., 35, 43 (1960). (3) Roe, D. A., Flesch, P., and Esoda, E. C. J., At. M. At. Atrch. Dermatol., 84, 213 (1961). (4) Swanbeck, G., Personal communication. (5) Swanbeck, G., Atcta Dermato_IZenereol., 39, Suppl. 43 (1959). (6) Holmes, A. W., Nature, 189, 923 (1961). (7) Brody, I., •7. Ultrastructure Res., 4, 267 (1960). (8) Schultz-Haudt, S. D., and Eeg-Larsen, N., Biochim. Biophys. Atcta, 46, 311 (1961). (9) Blomstrand, R., Fregert, S., and Nakayama, F., Atcta Dermato_IZenereol., 41, 281 (1961). (10) Flesch, P., Proc. Sci. Sect. Toilet Goods Atssoc., No. 29, 27 (1958). (11) Swanbeck, G., and Thyresson, N., dcta Dermato-IZenereol., 41, 289 (1961). (12) Achor, R. W. P., Winkelmann, R. K., and Perry, H. O., Proc. Staff Meetings Mayo Clinic, 36, 217 (1961). (13) Herdenstam, C.-G., Atcta Dermato_IZenereol., 39, 216 (1959). (14) Rothman, S., •7. rim. Med. Atssoc., 178, 38 (1961). (15) Dempski, R. D., Dissertation dbst., 21, 3007 (1961). (16) Blank, I. H., •7. Invest. Dermatol., 21, 259 (1953).