Lodén M
Department of Dermatology, University Hospital, Uppsala, Sweden.
Acta Derm Venereol. 1992 Sep;72(5):327-30.
Emollients can increase the water content in the stratum corneum by delivery of their water to the skin, and by occlusion. These two mechanisms were studied using three preparations with different concentrations of lipids. The products were applied to the skin and then removed by cleaning the surface after 5 and 40 min. The increase in skin water loss following removal of product residue was considered as a release of excess water in the skin. Exposure of the skin to pure petrolatum for 5 min gave no increase in the water loss from the skin surface following removal of the product residue. A lipid rich cream (66% lipids) gave a significant increase, but the highest increase was found after removal of an ordinary cream (27% lipids). Release of water from the skin indicates that water in the creams had previously been absorbed into the skin. The occluding properties of the products were determined after 40 min of exposure. Petrolatum reduced the water loss by approximately 50% and the other products by 16%. The occlusion caused an increase of water in the skin, which resulted in a release of water following removal of the products. The release was related to the reduction of water loss. Thus petrolatum gave a higher release of water than the other emollients.
润肤剂可通过将自身水分输送至皮肤以及形成封闭作用来增加角质层中的水分含量。使用三种不同脂质浓度的制剂对这两种机制进行了研究。将产品涂抹于皮肤上，5分钟和40分钟后通过清洁皮肤表面将其去除。去除产品残留后皮肤水分流失的增加被视为皮肤中多余水分的释放。皮肤暴露于纯凡士林5分钟后，去除产品残留后皮肤表面的水分流失并未增加。富含脂质的乳膏（脂质含量66%）导致水分流失显著增加，但去除普通乳膏（脂质含量27%）后水分流失增加最多。皮肤中水分的释放表明乳膏中的水分此前已被皮肤吸收。在暴露40分钟后测定产品的封闭性能。凡士林使水分流失减少约50%，其他产品使水分流失减少16%。封闭作用导致皮肤中的水分增加，从而在去除产品后导致水分释放。这种释放与水分流失的减少有关。因此，凡士林比其他润肤剂释放出的水分更多。
