MODERN TRENDS IN COSMETIC FORMULATION 197 ANM is sterile and possesses antiseptic properties which are doubtless due to the liberation of formaldehyde from unlinked methylol groups as in the case of the hydantoin methylol derivative above. A suspension of the treated starch in water has a pH of about 5.5-5-9, distinctly lower than that of the original starch (usually 7 or over). Here again the slight acidity may be ascribed to oxidation of traces of formaldehyde. ANM has been suggested as a component of deodorant and body dusting powders by reason of these antiseptic properties and its unimpaired absorbent power. Rice starch is used in the preparation. Modification qf shampoos. The increasing use of ethylene oxide and propylene oxide to form condensates with alcohols, amines and other compounds has led to a development in shampoo formulation which offers important advantages over the original salts of sulphated higher alcohols. The sodium salts of these sulphates are relatively insoluble in water and tend to form pastes or cloudy solutions. The triethanolamine salts have a much lower cloud point at equivalent concentrations but they are usually coloured, and discolour on exposure to light and in the presence of certain metallic ions such as the ferric ion, a particularly undesirable characteristic when pastel shades are desired. By condensing lauryl alcohol with two molecules of ethylene oxide, sulphating the resulting alcohol and neutralising with caustic soda a very viscous synthetic detergent, lauryl ether sulphate, is formed possessing remarkable properties. 8 Solutions of the sodium salt now have very low cloud points and the viscosity can be increased at appropriate concentrations by adding small amounts of sodium chloride. The viscosity can be raised in this way to the level of a clear gel. The ethoxylated product is now available as a clear water-white viscous liquid which does not discolour even in the presence of ferric ions. The lathering power and cleansing action are higher than for the salts of the straight sulphates, but it is usually necessary to incorporate foam building additives to any synthetic detergent in formulating a shampoo. ANALYSIS OF COMPLEX NATURAL PRODUCTS The analysis or taking apart of the relatively complex glycerides has for many years provided the cosmetic chemist with glycerin and a range of fatty acids and alcohols derived from them. From the acids and alcohols a very extensive range of emulsifying and surface-active agents are now manu- factured and the number has been vastly increased by reactions involving condensation with ethylene oxide. The mineral oils have been separated into a large number of components

198 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS and the many different fractions and types of compounds so isolated have given us raw materials with different properties to serve in the formulation of cosmetic products. The natural waxes are much more complicated, and the comparable analysis of lanol/n and beeswax has lagged behind the analysis of the fixed oils and fats. Lanolin is now beginning to take its place as a source of emulsifiers, surface-active agents and emollients and many interesting fractions and chemical derivatives of fractions of lanolin are now being produced, particularly in the U.S.A. ø They comprise the liquid and waxy fractions of the total lanolin and their derivatives produced by hydrogena- tion, acetylation and transesterification with isopropyl alcohol. The lanolin alcohols and their fractions with their esters and ethylene oxide condensates form another group of cosmetic raw materials. Furthermore the lanolin acids, their esters and alkylamine soaps complete the lanolin picture at the present time. As emulsifiers and stabilise•s some of the lanolin preparations exhibit properties not reproducible in materials derived from other sources. The elegance and functional performance of many cosmetic products will undoubtedly be enhanced by the adoption of selected materials from the lanolin range. The analytical treatment of beeswax has not proceeded as far as its unique properties, quite distinct from those of lanolin products, would appear to demand. The reason for this is in part the variation in the supply and cost of beeswax, and in part to a general belief that working specifica- tions are sufficiently rigid and tell all that need be known to establish a criterion of behaviour. The importance of a thorough study of beeswax has been mentioned in this Journal. TM RE-EXAMINATION OF SOME GENERALLY ACCEPTED HYPOTHESES "The silicones are anti-foaming agents." We may now turn to a rather different motivating factor influencing modern trends in formulation. It has been found that some generally accepted ideas have hindered development because they were accepted in too general form without proper scrutiny. For example, we were led to believe that the silicones are anti-foaming agents and we have probably all used them for this purpose. There are other circumstances in which they are not, and it must still be understood that these circumstances have not .yet been fully defined. The taboo on the use of silicones in conjunction with 5oaming agents such as shampoo materials was lifted in 1958 by the publi-