302 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS product (melanosome) is eliminated, a demand for more melanin granules is created. At this time it appears that within a decade or so it might be possible, by the use of chemicals, to increase or decrease at will the amount of pigment present in the skin and possibly also in the hair. The ability to control pigmentation in this way necessarily depends upon sound and exact knowl- edge of the processes involved in pigment formation. At present, there are three known ways in which alterations of skin color can be mediated by chemical means: (a) variations in the availability of pituitary hormones and certain other hormones, such as thyroid and estrogen, whose mech- anisms of action are still unknown (b) topical application of certain substances, such as hydroquinones and (c) oral ingestion of substances, such as psoralens, that can increase the response of the skin to ultraviolet light. Neither the mechanisms involved in these three categories of chemical control nor the stages in the pigmentation process at which the control is exerted by these agents are yet known. (Received November 12, 1963) REFERENCES (1) H. M. Fox and G. Vevers, The Nature o/Animal Co/ours, The Macmillan Co., New York, 1960. (2) J. B. Stanbury, J. B. Wyngaarden, and D. S. Fredrickson, Eds., The Metabolic Basis of Inherited Disease, The Blakiston Div., McGrawIHill Book Co., Inc., New York, 1960. (3) T. B. Fitzpatrick and A.D. Breathnach, Dermatol. IFochschr., 147, 481 (1963). (4) A. B. Lerner and T. B. Fitzpatrick, Physiol. Rev., 30, 91 (1950). (5) M. Seiji, K. Shimao, M. S.C. Birbeck, and T. B. Fitzpatrick, Ann. N.Y. Acad. Sci., 100, Pt. II, 497 (1963). (6) T. B. Fitzpatrick, S. W. Becker, Jr., A. B. Lerner, and H. Montgomery, Science, 112, 223 0950). (7) M. Seiji, T. B. Fitzpatrick, and M. S.C. Birbeck 5 t. Invest. Dermatol., 36, 243 (1961). (8) P. Masson, in M. Gordon, The Biology of Melanomas, Special Publ. N.Y. Acad. Sci., 4, 15 (1948). (9) M. S.C. Birbeck and N. A. Barnicot, in M. Gordon, Pigment Cell Biology, Academic Press, Inc., New York, 1959, pp. 549-561. (10) P. Drochmans, Arch. belg. dermatol., 16, 155 (1960).

J. soc. cos. CHEM. 15, 303--310 (1964) DETERMINATION OF ALLANTOIN AND THE ALUMINUM ALLANTOINATES IN VARIOUS COSMETIC AND PHARMACEUTICAL PREPARATIONS By SIDNEY A. K^TZ, Ph.D.,* RICHARD TURSR, PI•.D.,• and S. B. MEee^, B.S.{ ABSTRACT Procedures for the colorimetric determination of allantoin involv- ing removal of interfering substances by chloroform extraction have been developed. Their use for the determination of allantoin in a variety of cosmetic preparations is described. INTRODUCTION Because of their reported (1) therapeutic properties, allantoin and the aluminum allantoinates have been incorporated into various cosmetic preparations such as skin creams, lotions, lipsticks, and shaving prepara- tions. With the increasing use of allantoin in these products, suitable methods for the determination of allantoin and its aluminum derivatives are needed for quality control and product stability studies. Although the assay methods issued by the Board of Standards of the Toilet Goods Association (2) are well suited to the evaluation of the purity of allantoin, they are of little value in the determination of allantoin in complex cos- metic and pharmaceutical preparations because this method lacks speci- ficity. Interferences by antiseptics, antibiotics, quarternaries, lanolin derivatives and stearates lead to inaccurate results. Likewise, the color- imetric procedures of Young and Conway (3) and of E1 Ridi, Magd, and E1 Marsy (4) cannot be used directly. The colorimetric procedure of Domhas (5) is not applicable to the determination of allantoin in cosmetic and pharmaceutical preparations unless extensive separation and puri- fication techniques are employed. The chromatographic procedure of * Chemistry Dept., Rutgers University, Camden 2, N.J. • Pharmaceutical Labs. Div., Colgate-Palmolive Co., New Brunswick, N.J. $ Schuylkill Chemical Co., Philadelphia 32, Pa. 303