8O8 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Materials The materials used in the present study were obtained from the following sources: Fatty Acids Laurie acid, myristic acid, palmitic acid and stearic acid were ob- tained from the E. F. Drew Chemical Corp. These acids are marketed under the trade names of "Wecoline" 1295, "Wecoline" 1495, "Wecoline" 1695, and "Wecoline" 1892, respectively. Alcohols Lauryl alcohol ("Lorol" 11), cetyl alcohol ("Lorol" 24), and stearyl alcohol ("Lorol" 28) were obtained from the E. I. du Pont de Nemours and Co. Oleyl alcohol was supplied by Croda, Inc., myristyl alcohol by the Eastman Chemical Corp., and cholesterol by American Choles- terol Products. Sodium Lauryl Sulfate Sodium lauryl sulfate (Duponol* C) was obtained from the E. I. du Pont de Nemours and Co. EXPERIMENTAL RESULTS Sodium Lauryl Sulfate Systems Variation in Alcohols The addition of lauryl, myristyl, or cetyl alcohols to sodium lauryl sulfate systems increased emulsion viscosity and stability and decreased foam drainage. This is shown in Table I. Lauryl and myristyl alco- * Duponol is a registered trademark of E. I. du Pont de Nemours & Co., Wilmington, Del. Table I Variation in Alcohols-Sodium Lauryl Sulfate Syst½•ns • Foam Propcrties Emulsion Properties Drainage Stiffness Density Type of Alcohol b Viscosity Stability (60 min) (g) (g/cc) Discharge None Low 1 min 82 11 0. 055 Quiet Lauryl Medium 5 hr 0 40 0. 064 Slightly noisy Myristyl Medium 5 hr 0 38 0. 068 Noisy Cetyl Low to medium 5 hr 2 14 0. 062 Quiet Stearyl Low 5 min 71 12 0. 071 Quiet Oleyl High 30-60 min 84 10 0. 067 Quiet Cholesterol Low to medium 1-5 •nin 84 13 0. 061 Quiet Sodium lauryl sulfate concentration = 0.10 M. Sodium lauryl sulfate/aleohol ratio (molar) = 1' l.

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