SYNERGISTIC EFFECTS OF NONIONICS ON CATIONICS 591 8. The use of the hydrochloric acid salt of a tertiary amine which is a ger- micide and cationic in nature should be considered. Thus, it has been reported (32) that Vantocil©* lB, the hydrochloride salt of a polymeric biguanidine, is less inactivated than quaternary cationic surfactants by nonionic surfac- tants. Perhaps there are other similar amines which can be utilized. 9. A quaternary which exhibits atypical properties should be tried. One product falling into this category is Dowicil©* 100, which functions by gradually releasing formaldehyde. It has been used with good success to pre- serve many laboratory preparations of nonionic based cosmetic products. It is suggested that, by utilizing one or more of the above mentioned tech- niques to increase the cmc, it might be possible to decrease the inactivation of the germicidal agent and even possibly obtain synergistic germicidal ac- tivity of a cationic surfactant in the presence of a nonionic surfactant. (Received March 10, 1972) *ICI England, London, England. t Dow Chemical Co., Midland, Mich. (lO) (11) (12) t•EFERENCES (1) Dunngan, A. P., Microbiological conrol of cosmetics, Drug Cosmet. Ind., 102, No. 6, 43-5, 152-8 (1968). (2) Wolven, A., and Levenstein, I., Contaminated or not, TGA Cosmet. J., 1, 34-7 (1969). (3) Saad, H. Y., and Shay, E.G., App]ication of physical chemistry in product develop- ment, J. Soc. Cosmet. Chem., 23, 899-911 (1972). (4) Elek, S. D., Principles of antimicrobial activity, in Lawrence, C. A., and B]ock, S. S., Disinfection, Sterilization and Preservation, Lea and Febiger, Phila., Pa., 1968, p. 27. (5) CorpeL H. J., and Cobh, M., Some fundamental investigations on the resistance of tubercle baci]]i, J. Bacteriol. 35, 223-33 (1938). (6) Klarmann, E.G., Wrght, E. S., and Shternov, V. A., Pro]ongation of the antibacterial potential of disinfected surfaces, Appl. Microbiol., 1, 19-23 (1953). (7) James, M. A., Surface active agents in microbiology, Surface Activity and the Micro- bial Cell, S.C.I. Monograph No. 19, Society of Chemical Industry, London, 1965, pp. 3-23. (8) Gfiby, A. R., and Few, A. V., Lysis of protoplasts of Micrococcus lysodeikticus by ionic detergents, J. Gen. Microbiol., 23, 19-26 (1960). (9) DeLuca, P. P., and Kostenbauder, H. B., Inactivation of preservatives with macro- molecules. IV. Binding of quaternary ammonium compounds by nonionic agents. J. Amer. Pharm. Ass., Sci. Ed., 49, 430-7 (1960). Gershenfeld, L., and Stealman, R. L., The potentiating effects of various compounds on the antibacterial activities of surface-active agents. I, Amer. J. Pharm., 121, 249-66 (1949). Davies, G. E., Quaternary ammonium compounds. A new technique for the study of their bactericidal action and the results obtained with cetavlon (hexadecyltri- methylammonium bromide), J. Hyg., 47, 271-7 (1949). Ritter, H. W., The germicidal effect of a quaternary ammonium compound (cetyl- pyridinium chloride) on Mycobacterium tuberculosis, Appl. Microbiol., 4, 114-6 (1956).

592 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) Barr, M., and Tice, L. F., The preservation of aqueous preparations containing nonionic surfactants. II, ]. Amer. Pharm. Ass., Sci. Ed., 46, 442-5 (1957). Wedderburn, D. L., Preservation of toilet preparations containing nonion/cs, ]. Soc. Cosmet. Chem., 9, 210-28 (1958). Beckeft, A. H., and Robinson, A. E., The inactivation of preservatives by non-ion/c surface active agents, Soap, Perrum. Cosmet., 31,454-60 (1958). Moore, C. D., and Hardwick, R. B., Germicides based on surface-active agents, Mfg. Chem.,27, 305-9 (1956), and 29, 194-8 (1958). Delmotte, A. and Geeraerts, R., Considerations sur les Conditions dans lesquelles l'Addition de D•tersffs non-ion/ques peut d6terminer une Augmentation de l'Activit6 antiseptique de D•tersifs cationiques, Proc. lnt. Congr. Surface Activ., 4th, Brnsse]s, 3, 407-14 (1964). Delmotte, A., Anderung der antiseptischen Eigenschaften von Kationtensiden in Gegenwart von nichtionogenen Tensiden. I, Alkyldimethylbenzylammoniumchloride und Nonylpheno]5thylenexoid-Addukte', Tenside, 4, 217-20 (1967). Delmotte, A., Y, nderung der antiseptischen Eigenschaften yon Kationtensiden in Gegenwart von nichtionogenen Tensiden. II, Alkyldimethylbenzylammonimn chlo- ride and verschiedene nichtionogene Tenside, Ibid., 5, 13-7 (1968). Delmotte, A., and Caucheteur, G., Lowering of the antiseptic activity of 1,6-bis(4- amidino-phenoxy)hexane diisethionate, isopropanolamine lauryl sulfate, and hexa- chlorophene by contact with human skin and blood, Thetapie, 17, 53-62 (1962). Gucklhorn, L R., Antimicrobials in cosmetics, Mfg. Chem. Aerosol News, 40(6), 23- 30 (1969). Delmotte, A., Personal communication, February 23, 1969. Cantor, A., and Winicov, M. W., U.S. Patent 3,539,520 (November 10, 1970). Cowie, •[. M. G., and Sirianni, A. F., The solution properties of some polyoxyethy- lene-polyoxypropylene surfactants in nonaqueous solvents, ]. Amer. Oil Chem. Soc., 43, 572--5 (1966). Sehmolka, I. R., and Raymond, A. J., Mieelle formation of polyoxyethylene-polyoxy- propylene surfaetants, Ibid., 42, 1088-91 (1965). Schick, M. J., Effect of temperature on the critical miee]le concentration of nonion/e detergents. Thermodynamics of mieelle formation, ]. Phys. Chem., 67, 1796-9 (1963). Hsiao, L., Dunn/ng, H. N., and Harris, J. C., Critical mieelle concentrations of poly- oxyethylated non-ion/e detergents, Ibid., 60, 657-60 (1956). Ginn, M. E., Kinney, F. B., and Harris, J. C., Effect of temperature on critical mieelle concentration, ]. Amer. Oil Chem. Soc., 37, 183.. 7 (1960). Sheth, P. B., Solubilization and stabilization using surfaetants, Dis. Abstr. B28 ($), 974 (1967). Schick, M. J., Mieelle formation in mixtures of nonion/e and eationic detergents, ]. Amer. Oil Chem. Soc., 43, 681-2 (1966). Bouehal, A. W., U.S. Patent 2,921,885 (January 19, 1960). Gueklhom, I. R., Antimierobials in cosmetics, Mfg. Chem. Aerosol News, 41 (2), 30-3 (1970).