Determination of methyldibromoglutaronitrile in cosmetic products by high performance liquid chromatography with electrochemical detection

Rapid detection of undesired cosmetic ingredients by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

In recent years, cosmetic industry profits soared due to the widespread use of cosmetics, which resulted in illicit manufacturers and products of poor quality. Therefore, the rapid and accurate detection of the composition of cosmetics has become crucial. At present, numerous methods, such as gas chromatography and liquid chromatography-mass spectrometry, were available for the analysis of cosmetic ingredients. However, these methods present several limitations, such as failure to perform comprehensive and rapid analysis of the samples. Compared with other techniques, matrix-assisted laser desorption ionization time-of-flight mass spectrometry offered the advantages of wide detection range, fast speed and high accuracy. In this article, we briefly summarized how to select a suitable matrix and adjust the appropriate laser energy. We also discussed the rapid identification of undesired ingredients, focusing on antibiotics and hormones in cosmetics.

Final Report on the Safety Assessment of Methyldibromo Glutaronitrile

The halogen compound Methyldibromo Glutaronitrile is used in a wide variety of cosmetics as a preservative. Concentrations in cosmetic formulations reportedly range from 0.0075 to 0.06%. The oral LD50 in rats is 640 mg/kg. Dogs on a diet of 4,000 ppm Methyldibromo Glutaronitrile for 13 weeks developed thyroid hyperplasia; those on a diet of 167 ppm exhibited no hyperplasia, although the thyroid glands were enlarged. Application of Methyldibromo Glutaronitrile at a level of 4.0 g/kg to the skin of rats for 21 days produced severe irritation. A concentration of 0.025% applied to the skin of rabbits in a 28-day dermal toxicity study resulted in only slight to moderate irritation. No evidence of sensitization was found in guinea pig studies, nor was photosensitization reported in mouse studies. No reproductive or developmental toxicity was noted in two rat studies. Methyldibromo Glutaronitrile was not mutagenic in a series of mammalian system tests. Clinical data using repeat insult patch testing (HRIPT) methods indicated that concentrations as low as 0.025% produced a positive reaction in a few individuals. To limit the possibility that formulations containing this ingredient will lead to sensitization, it was concluded that leave-on formulations should contain 0.025% Methyldibromo Glutaronitrile. Rinse-off formulations, because the duration of exposure is much less, are considered safe as currently used