590 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS S.C. C. Annual Scientific Meeting Dec. 6, 1967 The Americana Hotel New York, N.Y.

.I. Soc. Cosmetic Chemists, 18, 591-598 (Sept. 1(5, 1967) Effect of Process Variables on the Stability of Some Specific Emulsions H. E. JASS, Ph.D.* Presented before the New York Chapter, January, 1966, New York City Synopsis--Three case histories of cosmctic emulsion problems involving rheological and emulsion deterioration with time are described. Despite considerable variation in emulsion type, the three demonstrated similar changes which are traced to changes in the physical state of the crystalline viscosity builders, primarily glyceryl monostearate. It is shown how changes in processing and formulation were able to arrest these changes and stabilize the product. The role of photomicrography in helping to analyze the problem and in predicting the results of experiments is demonstrated. INTRODUCTION The literature on emulsion theory, technology, and stability pre- diction is probably the most extensive portion of the cosmetic chemist's library. Yet, no other problem facing the chemist today poses as much mystery or demands an empirical approach as does emulsion formula- tion. Admittedly, the contributions of the many researchers in this area have been extremely valuable. They have advanced knowledge in this area to a considerable degree, affording the formulator a greatly superior springboard for his leap into the unknown. However, despite their noteworthy efforts, a cosmetic chemist, even after careful scientific preparation, still must adopt an optimistic attitude and must devote considerable time to testing to confirm his product's stability. Despite the large background of intuitive knowledge possessed by experienced and skilled chemists, publication has been scanty, to * Carter Products Div., Carter-Wallace, Inc., Cranbury, N.J. 08512. 591