348 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS forms clear solutions in mineral oil whereas the original product tends to precipitate and form cloudy solutions in oil. Lanolin forms waterAn-oil emulsions, one of the typical and best known characteristics of this product. The acetylated product does not form these emulsions, although it may be used in waterAn-oil preparations in low percentages to add emollience. It is, however, readily dispersed in the opposite type of emulsion, i.e., oil-in- water, and in soaps and shampoos, where it has a stabilizing effect on the foam. In addition, the modified product is waxy rather than tacky, and exhibits a marked odor change, from that typical of lanolin to a very faint, pleasant odor. Another change brought about by acetylation of lanolin is the increase in plasticity. The acetylated product retains an ointment- like consistency even at refrigerator temperatures whereas lanolin stiffens to the point where it is difficult to remove it from a collapsible tube. It is interesting to note that with the exception of water absorption, the acetylated product meets the requirements of lanolin U.S.P., although, of course, chemically it is quite different. ALLS•O•C REACTIONS Allergic reactions to lanolin are relatively rare. However, the wide- spread use of this product has increased the awareness of allergists and der- matologists to the existence of such reactions. A 1950 publication by Sulzberger and Lazar (10) indicated that the allergen responsible for sen- sitivity to lanolin was present in the mixed alcohol fraction. The presence of substantial quantities of hydroxyesters in lanolin, also known as wool fat, constitutes a major difference between wool fat and human skin fat. Our laboratory felt that it would be of value to investigate the allergic activity of our lanolin products which did not have free hydroxyls. Sulzberger's group was interested in testing these derivatives on lanolin-sensitive pa- tients. The findings of Sulzberger, Warshaw and Herrmann have been published (11, 12), and are probably known to you. Working with the acetylated and propionylated products which we prepared, they were able to show that these substances evoked significantly lower incidence of posi- tive skin reactions than did the original lanolin. Recently Everall and Truter (13) isolated the sensitizing factor as a yellow, glassy solid which appeared to be an impurity in the alcohol fraction. After acetylation of this substance, the product gave a negative result on patch testing. ACETYLATED LANOLIN ALCOHOLS As an extension of our investigation of acetylated lanolin, we carried out the same type of reaction on lanolin alcohols. These constitute approxi- mately 50 per cent oflanolin from which they may be separated by a series of steps involving saponification, extraction and purification. Lanolin alcohols consist of sterols, aliphatic alcohols, triterpenes, and a small per-

ACETYLATED LANOLIN DERIVATIVES 349 centage of hydrocarbons. The acetylation of the total alcohols did not result in a satisfactory product for use in cosmetic applications. However, after further investigation we obtained a low-viscosity, clear liquid fraction of acetylated alcohols* which has interesting new properties. Data on this product is presented on Table 3. TABLE 3--TYPICAL DATA ON LIQUID FRACTION OF ACETYLATED LANOLIN ALCOHOLS* Acid no ......................... 0.35 Hydroxyl no ..................... 2.0 Ester no ........................ 190.0 Soluble acids .................... Neutral to litmus by U.S.P. XIV method Viscosity ....................... 40 secon',ds Saybolt at 100øF. Melting point ................... Liquid at room temperature Color ........................... Pale yellow Odor ........................... Practically odorless Specific gravity .................. 0. 867 at 25øC. Solubility in water ............... None (hydrophobic)--no emulsification General solubility ................ Completely miscible in all proportions with the following: Mineral oil Ethanol 95% Castor oil Isopropyl myristate Vegetable oils Isopropyl palmirate Isopropanol Butyl stearate Silicone fluid #555 (DC) * Acetulan. T.M. This acetylated lanolin alcohol product is insoluble in water, but is sol- uble in all proportions in mineral oil, castor oil and vegetable oils. It is also miscible completely with 95 per cent ethanol, isopropanol, and Silicone Fluid #555 aswell as with isopropyl myristate, palmirate and butyl stearate. It is extremely hydrophobic and yet readily dispersed in the presence of emulsifying and dispersing agents, soaps and shampoos. The product is an emollient with unusual spreading and apparent penetrating character- istics. By modern concepts, emolliency involves either holding water to the skin or lubrication. This product performs both functions. Because of its chemical relationship to acetylated lanolin, it might be expected that the acetylated alcohol product would also have a low order of allergic activity against lanolin-sensitive persons. The paper previously cited by Everall and Truter (13) bears out this assumption. A report by the Industrial Toxicology Laboratories of Philadelphia confirms the in- nocuous effect of this acetylated lanolin alcohol product on a lanolin- sensitive patient. When larger numbers of lanolin-sensitive persons are available for testing, this work will be carried further. STABILITY STUDIES Studies were made to determine the effects of time, temperature and water on the stability of acetylated derivatives. Lanolin U.S.P. was used as a control. * Acetulan--Trade mark of American Cholesterol Products, Inc.