Dermal penetration and metabolism of p-aminophenol and p-phenylenediamine: application of the EpiDerm human reconstructed epidermis model.

To address the provision of the 7th Amendment to the EU Cosmetics Directive banning the use of in vivo genotoxicity assays for testing cosmetic ingredients in 2009, the 3D EpiDerm reconstructed human skin micronucleus assay has been developed. To further characterise the EpiDerm tissue for potential use in genotoxicity testing, we have evaluated the dermal penetration and metabolism of two hair dye ingredients, p-aminophenol (PAP) and p-phenylenediamine (PPD) in this reconstructed epidermis model. When EpiDerm tissue was topically exposed to PAP or PPD for 30 min (typical for a hair dye exposure), the majority (80->90%) of PAP or PPD was excluded from skin tissue and removed by rinsing.

Occurrence and hazard screening of alkyl sulfates and alkyl ethoxysulfates in river sediments.

Alkyl sulfates (AS) and alkyl ethoxysulfates (AES) are High Production Volume (HPV) 'down-the-drain' chemicals widely used globally in detergent and personal care products, resulting in low levels (ng to microg L(-1) range) ultimately released to the environment via wastewater. These surfactants have a strong affinity for sorption to sediments. However, data regarding the fate and effects following release into the environment has not been reported.

Molecular factor analysis applied to collections of NMR spectra.

It is often useful to identify and quantify mixture components by analyzing collections of NMR spectra. Such collections arise in metabonomics and many other applications. Many mixtures studied by NMR can contain hundreds of compounds, and it is challenging to analyze the resulting complex spectra.

Liquid chromatographic determination of the glutathione conjugate and ring-opened metabolites formed from coumarin epoxidation.

Species differences in the biotransformation of coumarin are thought to play an important role in its toxicity. Since the putative toxic metabolite is coumarin 3,4-epoxide (CE), methods to measure the metabolites of CE were developed. The glutathione (GSH) conjugate of CE (CE-SG) at the 3-position was purified by reversed-phase (RP)-high performance liquid chromatography (HPLC), and characterized by mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR).