Vanquerp V, Rodriguez C, Coiffard C, Coiffard L J, De Roeck-Holtzhauer Y
Laboratory of Industrial Pharmacy, School of Pharmacy, University of Nantes, France.
J Chromatogr A. 1999 Feb 5;832(1-2):273-7. doi: 10.1016/s0021-9673(98)00928-5.
Sunscreen agents are commonly used in cosmetic products to filter out noxious radiation in sunlight. A convenient high-performance liquid chromatographic (HPLC) method for the quantification of five sunscreens after irradiation has been selected. We used this analytical method to compare the photostability of benzophenone-3, PEG-25 PABA, octyl dimethyl PABA, 4-methylbenzylidene camphor and butyl methoxydibenzoylmethane, at levels in the range of 25-60 microM. The assay was carried out, using a C8 column with a methanol--water mobile phase. The detector was set at a wavelength of 300 nm. The assay was linear with the following limits: 0.2 microgram ml-1 for benzophenone-3, 1 microgram ml-1 for PEG-25 PABA, 0.15 microgram ml-1 for octyl dimethyl PABA, 0.1 microgram ml-1 for methylbenzylidene camphor and 0.05 microgram ml-1 for butyl methoxydibenzoylmethane. The half-lives calculated indicate a very good photostability of the sunscreens studied and permit to classify amongst themselves.
防晒剂常用于化妆品中，以滤除阳光中的有害辐射。已选择一种简便的高效液相色谱（HPLC）方法来定量辐照后的五种防晒剂。我们使用这种分析方法比较了二苯甲酮 - 3、PEG - 25对氨基苯甲酸、二甲基对氨基苯甲酸辛酯、4 - 甲基亚苄基樟脑和丁基甲氧基二苯甲酰甲烷在25 - 60微摩尔范围内的光稳定性。使用C8柱和甲醇 - 水流动相进行测定。检测器设置在300 nm波长处。该测定具有线性关系，限度如下：二苯甲酮 - 3为0.2微克/毫升，PEG - 25对氨基苯甲酸为1微克/毫升，二甲基对氨基苯甲酸辛酯为0.15微克/毫升，甲基亚苄基樟脑为0.1微克/毫升，丁基甲氧基二苯甲酰甲烷为0.05微克/毫升。计算得出的半衰期表明所研究的防晒剂具有非常好的光稳定性，并可对它们进行分类。
