Human metabolism and excretion kinetics of Bronopol after oral administration.

Bronopol is a preservative mainly used in various industrial applications, but also in cosmetics and pharmaceuticals. The aim of this study was to investigate the human toxicokinetics of Bronopol after oral administration. Five volunteers (two male and three female) were orally dosed with 9.715 mg Bronopol (0.100 to 0.154 mg/kg bw) and their urine was collected for 48 h. The samples were analyzed for the postulated metabolite 2-nitro-1,3-propanediol using an analytical human biomonitoring method. The maximum urinary concentrations of 1830-7666 µg/L (1981-5847 µg/g creatinine) were reached around 2.5 h (1.7-4.7 h) post dose. The excretion profile was monophasic with an average half life of 6.3 h (4.7-8.6 h). In total, 29.2% (19.5-35.9%) of the oral dose was excreted as 2-nitro-1,3-propanediol making it an amenable biomarker for the assessment of Bronopol exposure. The urinary excretion fraction can be used in population studies for the back-calculation of Bronopol intakes enabling an informed exposure and risk assessment of individual and population exposures.