Human systemic exposure to [14C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment

Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [14C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [14C] was measured in all materials, rinsing water, hair, plasma, urine and...

International ring trial of the epidermal equivalent sensitizer potency assay: Reproducibility and predictive-capacity

This study describes the international ring trial of the epidermal-equivalent (EE) sensitizer potency assay. This assay does not distinguish a sensitizer from a non-sensitizer, but may classify known skin sensitizers according to their potency. It assesses the chemical concentration resulting in 50% cytotoxicity (EE-EC50) or the 2-fold increase...

Xenobiotic metabolism in human skin and 3D human skin reconstructs: A review

In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental chemical exposure, it is also a potential...

Occupational exposure of hairdressers to [14C]-para-phenylenediamine-containing oxidative hair dyes: A mass balance study

We monitored the exposure of hairdressers to oxidative hair dyes for 6 working days under controlled conditions. Eighteen professional hairdressers (3/day) coloured hairdresser's training heads bearing natural human hair (hair length: approximately 30 cm) for 6 h/working day with a dark-shade oxidative hair dye containing 2% [14C]-para...

Human systemic exposure to a [14C]-para-phenylenediamine- containing oxidative hair dye and correlation with in vitro percutaneous absorption in human or pig skin

We investigated the absorption of a commercial [14C]-PPD- containing oxidative dark-shade hair dye in human volunteers as well as in vitro using human or pig ear skin. The hair of eight male volunteers was cut to a standard length, dyed, washed, dried, clipped and collected. Hair, washing water, materials used in the study and a 24-h scalp wash...

Urinary acetylated metabolites and N-acetyltransferase-2 genotype in human subjects treated with a para-phenylenediamine-containing oxidative hair dye

In the organism of mammals, important detoxification pathways of arylamines are catalysed by N-acetyltransferase 2 (NAT2). A recent case-control epidemiology study suggested that human NAT2 slow acetylators exposed to oxidative hair dyes may be at greater risk to develop bladder cancer. We therefore profiled urinary [14C]-metabolites and NAT2...

Acetyldinaline: A new oral cytostatic drug with impressive differential activity against leukemic cells and normal stem cells - Preclinical studies in a relevant rat model for human acute myelocytic leukemia

Acetyldinaline [CI-994; GOE 5549; PD 123 654; 4-acetylamino-N-(2'- aminophenyl)-benzamide] is the acetylated derivative form of the original compound Dinaline (GOE 1734; PD 104 208). The efficacy and toxicity of Acetyldinaline for remission-induction treatment of leukemia were evaluated and compared with those observed in previous studies of...