650 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table XV Animal and Vegetable Oils Approx Composition Mol Wt Viscosity (Lotion) (cps) Animal Egg oil Lanolin oil Mink oil Squalene Squalane Vegetable Jojoba Peanut Castor Safflower 62% glycerides, 33% phosphates, 5 % sterols ... Cholesterol, triterpenes, fatty acids ... C•4-C20 unsaturated triglycerides 852 Coo unsaturated aliphatic hydrocarbon 411 Ca0 saturated aliphatic hydrocarbon 423 Liquid wax (C20-C• esters)(half unsat.) 609 Triglycerides 864 90% ricinoleic triglyceride 935 Highly unsaturated triglycerides 942 6760 4680 9800 8680 6140 6880 10,010 6560 11,300 Initial Slip (Scale 1-5) End Feel (Scale 4-20) Castor 3.5 Lanolin oil 6.5 Jojoba 3.5 Castor 11.4 Mink 3.5 Mink 13.0 Egg 3.8 Egg 14.3 Peanut 4.0 Squalane 14.3 Safflower 4.0 Peanut 15.5 Lanolin oil 4.5 Safflower 15.5 Squalane 5.0 Squalene 17.3 Squalene 5.0 Jojoba 18.0 LANOLIN DERIVATIVES performed erratically (Table XVI). As previously noted, liquid lanolin gives very poor End Feel (6.5). Pure "lanolin alcohols" and lanolin alcohols ricinoleate are next (about 12.0), while lanolin itself gives a score of 15.8, substantially better than the con- trol lotion containing no emollient, but still not very good in comparison to the better emollients. Other lanolin derivatives (the acetate, a hydro- carbon extract, and isopropyl lanolate) gave fairly good results (16-17). The best of this series was isopropyl lanolate, which produced an End Feel almost 50% better than lanolin alcohols themselves. Table XVII is a regrouping of previous data to show all the ISO- PROPYL ESTERS together. These were often the best of each series originally tested. Note that isopropyl ricinoleate, with its hydroxy group as well as double unsaturation, and the linoleate, also with two unsatu- rated bonds, performed quite poorly. Isopropyl azelate, an odd-carbon (C9) fatty acid ester, gave a sligh:tly better result than the sebacate, an even-carbon (C•0) fatty acid ester of approximately the same molecular

EMOLLIENCY AND CHEMICAL STRUCTURE 651 Table XVI Lanolin and Derivatives Viscosity (Lotion)(cps) Lanolin (anhyd. USP) Liquid lanolin (oil) Lanolin alcohols Lanolin alcohols hydrocarbon extract Lanolin alcohols acetate Lanolin alcohols ricinoleate Isopropyl lanolate Initial Slip (Scale 1-5) Hydrocarbon extract 3.0 Alcohols 3.5 Acetate 3.8 Ricinoleate 4.5 Lanolin 4.5 Liquid lanolin 4.5 Isopropyl lanolate 5.0 7860 4680 39,500 10,720 13,560 8100 6400 End Feel (Scale 4-20) Liquid lanolin Alcohols Ricinoleate Lanolin Acetate Hydrocarbon extract Isopropyl lanolate 6.5 11.5 12.5 15.8 16.3 16.5 16.8 Table XVII Isopropyl Esters CHa O CHa--CH--O--C--R Approx Carbons on Viscosity Mol Wt Fatty Acid (Lotion)(cps) Branching Isopropyl myristate 271 14 2276 5.6 Isopropyl palmitate 299 16 5540 5.1 Isopropyl linoleate 320 18 1144 4.7 Isopropyl isostearate 321 18 5800 9.4 Isopropyl ricinoleate 337 18 4530 4.4 Isopropyl lanolate (10-32) 6400 P Diisopropyl adipate 228 6 800 13.1 Diisopropyl azelate 272 9 2040 11.0 Diisopropyl sebacate 286 10 6580 10.5 Initial Slip (Scale 1-5) Linoleate Sebacate Palmitate Myristate Isostearate Adipate Lanolate Azelate Ricinoleate 3.0 4.0 4.0 4.3 4.5 4.5 4.8 4.8 5.0 End Feel (Scale 4-20) Ricinoleate Linoleate Sebacate Azelate Isostearate Lanolate Myristate Palmitate Adipate 12 4 13 0 15 3 16 3 16 8 16 8 17.0 18.3 18.8