98 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Society of Cosmetic Chemists Medal Award to Henry Maso The Society of Cosmetic Chemists has presented its 1971 Medal Award to Mr. Henry Maso, a Vice President of Amerchol, Edison, N.J. The Medal Award, the Society's highest honor, is presented annually to the scientist or individual who has, over a period of years, contributed significantly to the advancement of cosmetic science, cosmetic scientists, and the cosmetic industry. The award was formally presented by Society President Morris Root at the December 13th luncheon session during the Society's annual meet- ing in New York City. Mr. Marshall Sorkin of Carter-Wallace served as Eulogist. k Le•t to right: Society President Morris Root, Medalist Henry Maso, and Eulogist Marshall Sotkin

]. Soc. Cosmet. Chem., 25, 99-114 (February 3, 1972) Clear Zinc Pyrithione Preparations TERRY GERSTEIN, M.S.* Presented May 24, 1971, Seminar, Washington, D.C. Synopsis--ZINC PYRITHIONE, also kn,own as zinc pyridine-2-thiol-l-oxide, has been es- tablished as an effective ANTISEBORRHEIC AGENT. Because of its limited aqueous solubility it is currently being marketed as a suspension in hair-cleansing and hair-grooming preparations. A method has been developed in which clear, aqueous (as well as nonaqueous) products can be prepared. The method is based upon the COMPLEXATION of zinc pyrithione with certain ORGANIC AMINES. It appears that zinc pyrithione is highly soluble in many primary aliphatic amines. In other more complex amines, such as the poly- alkylenimines, a definite stable molecular complex is formed. The ability of such amines to complex and produce a soluble form of zinc pyrithione is discussed with respect to the physical and d•emical properties of the ensuing solutions. Based on these findings, CLEAR HAIR Pi•EPARATIONS containing zinc pyrithione can be prepared for use as antidandruff cleansers, rinses, grooming agents, and conditioners. Ex- amples are offered of product formulations having levels of zinc pyrithione ranging from 700 to 20,000 ppm (2%). Analytical data concerning complex formation as well as the complexes' toxicology are presented. INTRODUCTION Zinc pyrithione, also known as zinc pyridine-2-thiol-l-oxide (ZPTO), has been established as an effective antiseborrheic agent (1). It is currently marketed in shampoo and hair dressings at concentration levels of about 0.5% in ,the hair dressing to about 1•o in the shampoo. This active ingredient is present in the form of a dispersed solid in these products since its solubility is quite limited in both water and oil media. The literature states that its solubility in water is 10-20 ppm at pH 7 and increases to 35-50 ppm at pH 8 (2). In ethanol, the solu- bility is 290 ppm in acetone, 700 ppm in benzene, 3-5 ppm and in diethylether, 0 ppm. In other solvents, the solubility increases--for * Revlon Research Center, Inc., 945 Zerega Ave., Bronx, N.Y. 10473. 99