Human pharmacokinetic profiles of propyl paraben after oral administration

Abstract

Parabens are commonly used as antimicrobial preservatives in consumer products. Because of possible endocrine disrupting activities, their safety has become a public concern. While pharmacokinetic studies on parabens have been reported in animal, it is not well known to the fate of parabens in human body following oral exposure. Thus, the aim of this study was to determine pharmacokinetic characteristics of propyl paraben (PP) in male subjects following single oral administration of 0.6 mg/kg bw of deuterium labeled-PP. Blood and urine were collected for 72 h, and concentration of free PP and metabolites

conjugates and hydrolysates were measured. In blood, free PP had 2 distinct phases in time-profile, while the metabolites followed first-order kinetics. The fraction of urinary excretion for total PP (free plus conjugates) was 8.6 %, whereas 38.7% of the administered dose was recovered in urine as sum of overall substances. The predominant metabolite excreted was p-hydroxyhippuric acid. Based on time-profiles, we constructed a multi-compartmental model and estimated kinetic parameters. PP was rapidly absorbed after oral ingestion and systemically distributed in humans. However, most of PP was likely to be metabolized prior to excretion, and rarely present in free form. The results of this study may be used for characterize PP exposure in the Korean population based upon biomonitoring data.