EMOLLIENT ACTION OF KUKUI NUT OIL 243 120 I I I .• 1 oo ß • 8o • 6o --• 4o ¸ • 20 0 I I I o 5 lO 15 20 Days at 60 degrees Figure 2. Stability of kukui nut oil measured at 60øC. Percentages of linolenate (C18:3n-3) remaining in kukui oil after incubation. Closed triangles, in air, no antioxidants open triangles, in air open squares, under N2 closed squares, under N2, no antioxidants. went down into the skin via the strippings. For this sample, total fatty acids were 251 •g/strip in the fifth stripping. Table I also shows the penetration of kukui oil into the skin. As with the control, there was less and less oil as one went down through the layers of the stratum corneum. The level of fatty acids in the fifth stripping (1037 •g/strip) was significantly higher than Table I Strippings of Control (no oil applied) and Kukui Oil PatcheP Control Kukui oil Stripping no. 1 2 3 4 5 2 3 4 5 C12 Laurate 73 70 42 18 26 123 22 91 80 C 14 Myristate 64 53 32 24 21 65 18 43 37 Unknown 133 16 8 0 8 0 0 0 0 C16 Palmirate 380 123 81 54 44 393 105 99 79 C16:ln-7 Palmitoleate 65 23 18 9 8 14 6 5 6 C 18 Stearate 119 66 51 22 30 86 52 46 36 C18:ln-9 Oleate 356 132 181 42 84 458 215 179 125 C18:2n-6 Linoleate 421 49 46 21 17 3234 529 415 264 C18:3n-3 Linolenate 307 30 31 74 10 1849 473 392 405 C20:ln-9 Eicosenoate 0 0 0 0 0 17 0 0 0 Total fatty acids 1922 564 495 266 251 6243 1424 1275 1037 Example is from subject A. Units are p,g fatty acid/stripping.

244 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS it was in the control, demonstrating the penetration of kukui oil through the skin. In addition, it may be seen that the fifth stripping on the patch of skin to which kukui oil had been applied had a fatty acid profile roughly characteristic of kukui oil with high levels of linoleate (C 18:2n-6) and linolenate (C 18:3n-3). Data averaged from all three volunteers suggested that total fatty acid levels were 234 --- 67 pug/strip at the fifth stripping for control (no oil applied), 824 --- 616 pug/strip at the fifth stripping for kukui oil, and 834 --- 311 }zg/strip at the fifth stripping for coconut oil. Much the same effects were seen when oil was applied at half dose (data not shown). Oils penetrated the stratum corneum but were deposited at lower levels than when applied at the full doses described above. Averaged values for fifth strippings for two subjects were 430 pug/strip and 480 pug/strip for kukui and coconut oils, respectively. While coconut oil penetrated the skin, the nature of the oils left in the skin was very different than when using kukui oil. Figure 3 shows that coconut oil left lipids com- posed largely of saturated fatty acids while kukui oil left lipids composed of a mixture of saturated, monounsaturated, and polyunsaturated fatty acids. Lotion left a disproportionate percentage of oil in the skin. Lotion contained only 13% oil, which is much less than the neat oils. However, as indicated in METHODS, lotion was applied at higher rates (50 mg = 50 pub as compared with 20 pul of full doses of the neat oils. Hence, oil application rates of the lotion compared with full doses of the neat oils were 50/20 x 0.13 = 32.5%. About 65% as much oil was applied with the 40 50 20 10 o o,4 -• CQ o-) CQ • • Z Z Z 0 0 Figure 3. Fatty acid profiles of skin strippings treated with coconut oil (cross-hatched) or kukui nut oil (open bars with line).