DIMETHYL SULFOXIDE 847 REFERENCES (1) Elfbaum, S. G., and Laden, K., Mechanism of action of dimethyl sulfoxide: Part I, J. Soc. Cosmetic Chemists, 19,119-27 (1968). (2) Elfbaum, S. G., and Laden, K., Mechanism of action of dimethyl sulfoxide: Part II, Ibid., 19,163-72 (1968). (3) Van Holde, K. E., and Sun, S. F., Bovine serum albumin in watcr-dioxane mixtures, J. Am. Chem. Soc., 84, 66-72 (1962). (4) Stougton, R. B., Dimcthylsulfoxidc (DMSO) induction of astcroid reservoir in human skin, Arch. Dermatol., 91,657-60 (June 1965). (5) Stoughton, R. B., Hcxachlorophcnc deposition in human Stratum comeurn, Ibid., 94, 646-8 (Nov. 1966). (6) Price, V. H., and Mcncfce, E., On the effect of dimethyl sulfoxidc on hair kcratin, J. Invest. Dermatol., 49,297-301 (1967). (7) Swccncy, T. M., Dowries, A.M., and Matoltsy, A. G., The effect of dimethylsulfoxide on the epidermal water barrier, Ibid., 46,300 (1966). (8) Crounsc, B. G., The association of lipids with keratinous proteins of human callus. Ibid., 46,550-4 (1966). (9) Elfbaum, S. G., and English, M. ¾., unpublished observation.

J. Soc. Cosmetic Chemists, 19, 849-862 (Dec. 9, i968) A Permanent Wave its Performance and of Action Neutralizer: Mechanism J. LEON LICHTIN, Ph.D.,* A. WILLIAM FORBRIGER, Ch.E.,} and C. R. REISS, M.S.E.-• Presented December 6, 1967, New York City Synopsis--A bromate-based permanent wave neutralizer, modified by the addition of at least 24% magnesium sulfate (U.S.P.), has been found to improve the stability of waved tresses in water and, more markedly, in air. A determination of its mechanism of action indicated a combination of effects responsible for its beneficial action. Among these effects are: charge neutralization, uptake of the added salt, and re-formation of hydrogen bonds. To be effective, the added salt must be applied concomitantly with the oxidant, thus re- forming both disulfide and secondary bonds at the same time, a process labeled "parallel waving." The modified neutralizer, compared to bromate, appears to produce a greater degree of hydrogen bond re-formation which (together with its other effects) demonstrates how secondary bonding can promote improved waving performance. INTRODUCTION Permanent waving in its simplest aspect consists of wrapping the hair on a mandrel and then treating it chemically to break down the primary (disulfide) and the secondary (salt and hydrogen) linkages of the keratin, this breakdown followed by the re-formation of these same linkages (1). In the formulation of solutions for permanent waving, the prime con- cern has been the ability of reagents, suitable for human use, either to * College of Pharmacy, University of Cincinnati, Cincinnati, Ohio 45221. t The Realistic Company, 3274 Beekman Street, Cincinnati, Ohio 45223. 849