The different decomposition properties of diazolidinyl urea in cosmetics and patch test materials.

Background: Diazolidinyl urea is a formaldehyde-releasing compound that releases formaldehyde through its decomposition. However, there have been few reports about the decomposition properties of diazolidinyl urea in cosmetics and patch test materials.

Objectives: The aim of this study was to show how diazolidinyl urea decomposes in cosmetics and patch test vehicles, and to determine which cosmetic compounds should be evaluated in patch test studies of diazolidinyl urea.

Method: We fractionated diazolidinyl urea-dissolving buffers or diazolidinyl urea-containing cosmetics with high-performance liquid chromatography-photodiode array detector (HPLC-PDA), and characterized them in liquid chromatography-mass spectrometry (LC-MS) and (1) H-nuclear magnetic resonance studies. Diazolidinyl urea-containing cosmetics and diazolidinyl urea patch test materials were also analysed with HPLC-PDA and LC-MS.

Results: Diazolidinyl urea was decomposed to (4-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (HU) and (3,4-bis-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (3,4-BHU) in most of the cosmetic samples tested. The peak patterns of the patch test materials analysed with the HPLC-PDA were different from those of the cosmetic samples. CONCLUSIONS. The diazolidinyl urea-derived decomposition products differed between the cosmetics and patch test preparations. To test the contact sensitivity of the diazolidinyl urea present in cosmetics, patch tests with HU and 3,4-BHU in petrolatum should be performed.