Absorption of triphenylmethane dyes Brilliant Blue and Patent Blue through intact skin, shaven skin and lingual mucosa from daily life products

Abstract

Currently, there is evidence of health risks of triphenylmethane dyes after systemic absorption. This paper investigates the fate of Brilliant Blue (BB) and Patent Blue (PB) after 24-h in vitro diffusion, firstly through intact and secondly through shaven pig-ear skin (stored by freezing) from four leave-on cosmetics under in-use conditions. Both dyes showed no measurable permeation through intact skin but significant permeation was found through shaven skin. From 250 ng/cm(2) of dye in one applied dose there were found 52 ng/cm(2) of BB and 91 ng/cm(2) of PB from ethanol-based after-shave, 39 ng/cm(2) of BB and 86 ng/cm(2) of PB from ethanol-free facial-cleanser, 35 ng/cm(2) of BB and 43 ng/cm(2) of PB from O/W emulsion, and no amount from W/O emulsion, as available to become systemically absorbed. Thirdly, the paper focuses on lingual mucosa after licking lollipops. Ex vivo porcine tongue dorsum was exposed to human saliva with 15,000 ng/cm(2) of dye for 20 min. 24-h diffusion resulted in 34 ng/cm(2) of BB and 86 ng/cm(2) of PB which can be directly absorbed into the blood system. Findings are troubling, particularly with regard to the frequent use of after-shave products by the male population and repeated lollipops licking by children.