$68 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 4.0 3.0 2.0 !.0 S 0.6 0.4 0.2 0.! 55 60 65 70 75 OIL CONTENT (%) Figure 5. The occlusive thickness (S) of white petrolatums of different oil contents is shown as a function of the oil content in a semilog plot acterizing a product by calculating an "occlusive thickness" permits com- parison ot5 the effect o15 products on transepidermal moisture loss. (Received August 5, 1970) REFERENCES (1) Blank, I. H., Factors which influence the water content of the stratum corneum, J. Invest. Dermatol., 18, 433-40 (1952). (2) Powers, D. H., and Fox C., A Study of the effect of cosmetic ingredients, creams and lotions on the rate of moisture loss from the skin, Proc. Sci. Sect. Toilet Goods Ass., 28, 2 I-6 (1957). (3) Thiele, F. A. J., and Schutter, K., A new micro method for measuring the water balance of the human skin. Salt crystal method. I. Apparatus, J. Invest. Dermatol., $9, 95-103 (1962). (4) Thiele, F. A. J., and Schutter, K., Moisture meters for measuring the water-balance of the human skin, Proc. Sci. Sect. Toilet Goods Ass., 40, 20-4 (1963). (5) Spruit, D., and Malten, K. E., The regeneration rate of the water vapor loss of heavily damaged skin, Dermatologica, 132, 115-23 (1966). (6) Spruit, D., and Malten, K. E., Epidermal water-barrier formation after stripping of normal skin, J. Invest. Dermatol., 45, 6-14 (1965). (7) Spruit, D., Measurement of the water vapor loss from human skin by a thermal conduc- tivity cell, J. Appl. Physiol., 23, 944-7 (1967). (8) Baker, H., and Kligman, A.M., Measurement of transepidermal water loss by electrical hygrometry, Arch. Dermatol., 96, 441-52 (1967).

]. Soc. Cosine*. Chem., 22, 369-377 (May 27, 1971). The Accumulation and of Antibacterial Agents in Human Skin Persistence DAVID TABER, Ph.D.,* JOHN C. LAZANAS, Ph.D.,* OTIS E. FANCHER, Ph.D.,* and JOSEPH G. GALANDRA, M.D., Ph.D.* Synopsis--With the use of daily applications of a mixture of labeled HEXACHLOROPHENE and TRICLOCARBAN (3,4,4'-trichlorocarbanilide) in a soap vehicle, the accumulation and persistence of radioactivity on the dorsal surface of the hand were measured for five days. After the fourth application the amount remaining on the skin after rinsing seemed to ap- proach equilibrium. During any one day the amount of antibacterial ingredients decreased by 50%. The accumulation of antibacterial agents on the SKIN may explain the observation that the effect of ANTIBACTERIAL SOAP on the microflora of the skin is related to the number of exposures. INTRODUCTION It is a peculiarity of washing with antibacterial soaps or detergents that the antibacterial agents are deposited onto skin from vehicles whose function it is to remove substances from the skin surfaces. Although the mechanism whereby these agents are deposited is poorly understood (1, 2), the molecular structure of the deposited material (3-6) and the nature of the vehicle (7-9) are involved. Deposition of particles on skin is stated (10, 11) to be related to the psi and zeta potentials of the skin and the par- ticles. Several techniques have been used to measure the quantity of chemi- cals deposited on viable skin from different types of vehicles. Compeau * Research and Development Department, Armour-Dial, Inc., 3115 South Benson St., Chi- cago, Ill. 60608. *Industrial BIO-TEST Laboratories, Inc., 1810 Frontage Road, Northbrook, Ill. 60062, where investigation was conducted. 369