PROPERTIES OF ETHOXYLATED LANOLIN Table IV Perfume Solubilization Using Lanolin Ethoxylates in a 9.0% SDA-40 Ethanol/80% Water Medium at 68øF • 529 Perfume Type Concentration PEG-75 PEG-75 Laneth-16 Laneth-10 % Wt Lanolin Oil Lanolin Acetate A 4 D D D I 8 D D C I B 4 D D D I 8 D D C I C 4 I D I I 8 D D C C D 4 I D D I 8 I D I C E 4 D D D I 8 D D D D aC: clear solution, (best) D = dispersible, milky solution, (in bet•veen) I = insoluble (two distinct phases), (worse). should be recognized that fragrance compounds of this type and quality are usually prepared in cologne bases containing 75 to 85 per cent alcohol and not vice versa as was done in this experiment. Most likely, many more of the samples prepared would have produced a clear product if just chilled, then filtered. The purpose of this study was to place emphasis on the solubilizing power of the lanolin ethoxylates under the poorest possible condition of rela- tively high fragrance levels and low alcohol content. In formulating a gel shampoo, one must consider its viscosity stability. Of- ten times, gel shampoo viscosities increase or decrease rapidly to a point where they are no longer usable. The gel shampoo control used in this experi- ment (Table I ) showed a rapidly decreasing viscosity over the 2-month study. The ethoxylated lanolin and lanolin alcohol additives in most cases stabilized the gel shampoo viscosity after its initial decrease. In every case, except when the PEG-24 Hydrogensted Lanolin and the Laneth-16 were added, the vis- cosity of the solid gel changed to a free-flowing gel or a liquid with increased concentrations. These exceptions produced increases in viscosity. Laneth-16 produced a very viscous thermally stable gel having good viscosity stability. The PEG-24 Hydrogensted Lanolin showed poor thermal stability. It appears that in most cases, 5 or 10 per cent ethoxylate levels produced the greatest viscosity stability during the test period with correspondingly acceptable thermal stability. Laneth-10 Acetate demonstrated poor stability at 68øF with a sudden decrease in viscosity when 20 per cent was used as an additive. Additionally, new data on the pigment wetting performance of lanolin ethoxylates will be the subject of a future investigation. Preliminary studies

530 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS indicate that the PEG-75 Lanolin oil may be a superior dispersing agent for inorganic pigments, especially iron oxides. A study presented in 1964 demonstrated that lanolin derived solubilizers are effective in solubilizing water insoluble bateriostats in soap and detergent solutions (3). Some newer bacteriostats, not presented in that study, were evaluated using the Laneth-16 derivative as the solubilizer. The results were comparable to the 1964 study. Various properties of lanolin ethoxylates have been presented in this paper, and it is quite evident that these properties lend to their marked versatility in cosmetic applications. Illustrations involving the perfume solubilization power of ethoxylated lanolin derivatives under extremely unfavorable conditions were given. Also demonstrated here was the viscosity control of an anionic gel shampoo sys- tem using these ethoxylates. In conclusion, we hope that we have demonstrated how these multifunc- tional lanolin ethoxylates may be effectively utilized in future cosmetic de- velopments. ACKNOWLEDGMENTS The authors are indebted to Dr. Harold Silverman and his staff at the Massachusetts College of Pharmacy for their cmc and specific gravity deter- minations and the cosmetic research staff at International Flavors and Fra- grances, Inc., for their cooperation in the perfume compound solubilization studies. (Received August 13, 1974) REFERENCES (1) P. Becher, Emulsions: Theory and Practice, Vol. 1, Reinhold Publishing Corp., New York, 1957, Pp. 34-8. (2) H. Y. Saad and E. G. Shay, Application of physical chemistry in product develop- ment, ]. Soc. Cosmet. Chem., 23, 899-911 (1972). (3) K. L. Russell and S. G. Hoch, Water-insoluble bacteriostats solubilized in soap and detergent solutions, ]. Soc. Cosmet. Chem., 16, 169-84 (1965).