Abstract:

In order to study the transdermal absorption characteristics and skin irritation of the fluorescent whitening agents （FWAs） in the facial mask, the content of 5 pyrazoline fat-soluble FWAs in the receiving solution was determined by high performance liquid chromatography triple quadrupole liquid chromatography mass spectrometry （HPLC-MS/MS） with the modified Franz transdermal diffusion cell and the abdominal skin of male rats in vitro. The cumulative penetration amount of 5 pyrazoline fat-soluble FWAs at different time points was calculated, and the FWAs remained in the skin was detected at the end of the experiment. The skin irritation test was carried out using rabbits according to the requirements of skin irritation test in “Safety and Technical Standards for Cosmetics” （2015 Edition）. The results show that there is good linear relationship between the five fat-soluble FWAs determined by HPLC-MS/MS in their respective concentration ranges. The correlation coefficients （r ²） are all greater than 0.999. The detection limits are 0.5-10.0 pg and the lower limits of quantification are 2.0-30.0 pg. The average recoveries and relative standard deviations are 95.2%-102.1% and 1.8%-4.2%, respectively. The liposoluble FWAs C.I.162 in the mask could penetrate into the skin, and the transdermal diffusion within 0-36 h is in accordance with zero order kinetics equation. C.I.135, C.I.185, C.I.367 and C.I.368 are absorbed in the skin but not through the skin in a short period. Skin irritation test shows that 5 pyrazoline liposoluble FWAs in facial mask have no irritation on rabbit skin. It is suggested that the fat-soluble FWAs are easy to migrate to the stratum corneum or subcutaneous layer of the skin and have no iiritating effect on mammalian skin.

Key words: facial mask, fluorescent whitening agents （FWAs）, transdermal absorption, skin irritation, HPLC-MS/MS