Organic and Inorganic Pigments from Commercial Inks Used in Eyebrows’ Microblading: Approach for Assessing the Safety Use by Bacterial Reverse Mutation Assay

Abstract

Background and Objective: The aesthetic products’ safety should not be neglected to the detriment of the market. This study aimed to evaluate the mutagenic potential of commercial inks. It was formulated with organic (P1) and inorganic (P2) pigments for eyebrows microblading using a validated method by regulatory agencies, the Salmonella/microsome assay, to assure the safety of use. Methods: The assay was carried out in three steps: preliminary toxicity, medium without (−S9), and presence (+S9) of metabolic activation. The strains, auxotrophic to histidine (His-) TA97a, TA98, TA100, and TA102, were exposed to both types of inks, in triplicate, compared to negative and positive controls. Data were statistically analyzed, and values with mutagenic index ≥ 2.0 were indicative of mutagenicity. Results: The inks with organic (P1) and inorganic (P2) pigments were not toxic to TA98 and TA100 S. typhimurium tester strains, even at concentrations applied in humans. Both inks were not mutagenic either in the absence or presence of metabolic activation in the tested concentrations, including that applied in humans. The assay showed that P1 and P2 were not direct (−S9) or indirect (+S9) mutagens as commercially formulated. Conclusions: These results indicate that applying these inks on organisms with microsomal enzymes, including humans, is safe since no compound in the inks became more toxic to induce the bacterial reverse mutation.