Unilever HPC-NA, Trumbull, CT, USA.
J Cosmet Dermatol. 2010 Sep;9(3):202-10. doi: 10.1111/j.1473-2165.2010.00510.x.
A mild moisturizing body wash with stearic acid, a key component of corneum lipids, and emollient soybean oil has been introduced in the market place. The objectives of this study are to determine the amount and the location of the stearic acid in the corneum after in vivo cleansing by the formulation.
Clinical cleansing studies for one and five consecutive days were carried out with the formulation containing soybean oil or petroleum jelly (PJ). The free stearic acid in it was replaced by the fully deuterated variant. The amounts of stearic acid in 10 consecutive corneum tape strips were measured by liquid chromatograph-mass spectroscopy. Separately, electron paramagnetic resonance (EPR) measurements were taken with a porcine skin after a wash by the soybean oil formulation with its free fatty acid replaced by its spin probe analogue, 5-doxyl stearic acid.
Deuterated stearic acid was detected in all 10 consecutive layers of stratum corneum and the total amount after five washes with the soybean oil formulation was 0.33 μg/cm². The spin probe in cleanser-treated skin was incorporated in a partially ordered hydrophobic region similar to corneum lipids. The probe mobility increased in the temperature region where lipid disorder was expected.
The estimated total fatty acid delivered to skin from cleansing is comparable to the amount of fatty acid in a corneum layer. The delivered fatty acid is most likely incorporated in the corneum lipid phase.
市场上推出了一种含有硬脂酸（角质层脂质的关键成分）和润肤剂大豆油的温和保湿沐浴露。本研究的目的是确定配方在体内清洁后硬脂酸在角质层中的含量和位置。
对含有大豆油或凡士林（PJ）的配方进行了为期一天和连续五天的临床清洁研究。其中的游离硬脂酸被完全氘代变体取代。通过液相色谱-质谱法测量了 10 个连续角质层胶带中的硬脂酸含量。另外，用含有游离脂肪酸的大豆油制剂对猪皮进行了电子顺磁共振（EPR）测量，其游离脂肪酸被其自旋探针类似物 5-二氧代硬脂酸取代。
在所有 10 个连续的角质层层中都检测到了氘代硬脂酸，并且在用大豆油制剂洗涤五次后的总量为 0.33μg/cm²。清洁剂处理过的皮肤中的探针被整合到类似于角质层脂质的部分有序疏水区。探针的流动性在预期脂质无序的温度区域增加。
从清洁中输送到皮肤的估计总脂肪酸与角质层中脂肪酸的量相当。输送的脂肪酸很可能被整合到角质层脂质相中。
