184 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 26) Chung, H. L., Ts'ao, W. C., Hsu, H. C., Kuo, C. H., K'o, H. Y., Mo, P.S., Chang, H. Y., Chuo, H. T., and Chuo, W. H., Hexachlorophene (G-11) as a new specific drug against clonorchiasis sinensis: its efficacy and toxicity in experimental and human infection, Ibid., 82, 691 (1963). 27) Wit, J. G., and Van Genderen, H., Some aspects of the fate of hexachlorophene [2,2'-methylenebis(3,4,6-trichlorophenol)] in rabbits, rats, and dairy cattle, Acta Physiol. Pharmacol. Need., 11, 123 (1962). Analytical and Research Laboratory, islip, N.Y., 1952. Draize, J. H., Woodard, G., and Calvery, H. O., Methods for the study of irritation and toxicity, J. Pharmacol. Exptl. Therap., 82, 377 (1944). 30 Nickerson, M., University of Michigan, Ann Arbor, Mich., 1954. 31 Kehoe, R. A., Physiologic response of experimental animals to the absorption of Actamer and G-I 1, Rept. of Kettering Laboratory, Cincinnati University, Cincinnati, Ohio, 1953. 32) Schwartz, L., Warren, L. H., and Goldman, F. H., Public Health Rept. (U.S.), 55, 1158 (1940). 33 Traub, E. F., Newhall, C. A., and Fuller, J. R., The value of a new compound used in soap to reduce the bacterial flora of the human skin, Surg., Gynecol. Obstet., 79, 205 (1944). Udinsky, H. J., Reduction in total skin flora by the daily use of a soap containing dihydroxyhexachlorodiphenylmethane, J. Med. Soc. New Jersey, 42, 15 (1945). Schwartz, L., Comparing the irritant action of soaps, Ann. Allergy, 8• 530 (1950). Epstein, E., Dichlorophene allergy, Ibid., 24, 437 (1966). Suskind, R. R., Percutaneous Toxicity, in Sternberg, T. H., and Newcomer, V. D., The Evaluation of Therapeutic Agents and Cosmetics, McGraw-Hill Book Co., New York, 1964, pp. 179-82. Shelanski, H. A., and Shelanski, M. V., A new technique for human patch tests, Proc. Sci. Sect. Toilet Goods Assoc., 19, 46 (1953). Draize, J. H., Procedures for the appraisal of chemicals in foods, drugs, and cosmetics. VIII, Dermal toxicity. Food, Cosmetic Law ]., 10, 722 (1955). Industrial Biology Labs., Philadelphia, Pa., 1952 and (repeated) 1966. Edelson, E., Newark City Hospital, Newark, N.J., 1965. Wilkinson, D. S., Photodennatitis due to tetrachlorosalicylanilide, Brit. ]. Dermatol., 73, 213 (1961). Jillson, O. F., and Baughman, R. D., Contact photodermatitis from bithionol, Arch. Dermatol., 88, 409 (1963). O'Quinn, S. E., Kennedy, C. B., and Isbell, K. H., Contact photodermatitis due to bithionol and related compounds, ]. Am. Med. Assoc., 199, 125 (1967). Freeman, R. G., and Knox, J. M., The action spectrum of photocontact dermatitis by halogenated salicylanilides and related compounds, Arch. Dermatol., 97, 130 (1968). Epstein, J. H., Wuepper, K. D., and Maibach, H. J., Photocontact dermatitis to halogenated salicylanilides and related compounds, Ibid., 97, 236 (1968). Wilkinson, D. S., Patch test reactions to certain halogenated salicylanilides, Brit. ]. Dermatol., 74, 302 (1962). Baughman, R. D., Contact photodermatitis from bithionol, II, Cross-sensitivities to hexachlorophene and salicylanilides, Arch. Dermatol., 90, 153 (1964). Gaul, L. E., Sensitivity to bithionol, Ibid., 81, 600 (1960). Epstein, E., Allergy to dermatologic agents, ]. Am. Med. Assoc., 198, 517 (1966). Litchfield, V. T., and Wilcoxon, F., A simplified method of evaluating dose-effect experiments, ]. Pharmacol. Exptl. Therap., 96, 99 (1949). Nickerson, M., University of Utah, Salt Lake City, Utah, 1949. 28) (29 (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) 45) 46) (47) (48) (49) (50) (51) (•)

J..%c. Cosmetic Chemists, 20, 185-198 (March 4, 1969) Effect of Initial Surfactant Location on Emulsion Phase Inversion TONG JOE LIN, Ph.D., and JOHN C. LAMBRECHTS, B.S? Presented May 14, 1968, Filth IFSCC Congress, Tokyo, Japan Synopsis The voluxne of the internal phase at the point of inversion, q•, was examined as a function of the initial surfactant distribution in the oil phase and the aqueous phase. Experimental data obtained with a series of nonionic surfactants and two types of oils indicated that, in addition to the type of surfactants, the initial distribution of the surfactant played an important role in determining the type of emulsion formed. Placing of more hydrophilic surfactant in the aqueous phase initially favored a formation of an O/W emulsion and increased the value of q•. The experimental data suggested that the rate of migration of the hydrophilic surfactant from the oil phase to the aqueous phase was not instantaneous but required a finite time. The results were qualitatively consistent with the theory of Davies. INTRODUCTION Since the type of emulsion often has significant effects on viscosity and texture, as well as stability, controlling phase inversion is important to cosmetic chemists not only from the product development viewpoint but also [rom the manufacturing viewpoint. Although phase inversion of an emul- sion is a well-known and widelv encountered phenomenon, the precise mechanism is not well understood. Among the many factors which influence the emulsion type, the surfactant employed to stabilize the emulsion is considered very important. In an earlier work, the writer discovered that, in addition to the surfactant type and concentration, the initial surfactant location prior to emulsification also Max Factor and Company, 1655 North McCadden Place, Hollywood, Calif. 90028. 185