Pharmacokinetics of bisphenol A in humans following a single oral administration.
Level 4 - case-series / case-control
Single-arm experimental pharmacokinetic study in humans without a comparator group
PubMed 26115537 · doi:10.1016/j.envint.2015.06.008
What was done
Fourteen healthy human adults (six men, eight women) ingested a single oral dose of 100 μg/kg body weight of deuterated bisphenol A (d6-BPA) to distinguish administered compound from background native BPA. Blood and urine samples were collected and analyzed over a three-day period to measure oral absorption rate, serum elimination kinetics, half-life, area under the curve, urinary excretion, and metabolism to glucuronide and sulfate conjugates.
What was found
Mean total (conjugated and unconjugated) serum d6-BPA peak concentration (Cmax) reached 1711 nM (390 ng/ml) at a Tmax of 1.1 ± 0.50 hours. Unconjugated d6-BPA appeared in serum within 5 to 20 minutes with a mean Cmax of 6.5 nM (1.5 ng/ml) at 1.3 ± 0.52 hours, comprising less than 1% of total d6-BPA in blood across all time points. Terminal elimination half-lives were 6.4 ± 2.0 hours for total d6-BPA and 6.2 ± 2.6 hours for unconjugated d6-BPA. Total recovery of administered d6-BPA in urine was 84% to 109%, with 10 of 14 subjects excreting >90% as metabolites within 24 hours. Detectable blood concentrations near the limit of detection (0.001 to 0.002 ng/ml) were observed at 48 hours in some subjects.
Why it matters
This study provides direct quantitative human pharmacokinetic parameters showing that orally ingested bisphenol A undergoes rapid and nearly complete first-pass conjugation, leaving less than 1% in the active unconjugated form in circulation, with the majority excreted in urine within 24 hours.
Limits
The study had a small sample size (n = 14) and evaluated only a single bolus oral dose (100 μg/kg), without assessing repeat-dose kinetics, chronic low-level exposures, or non-oral routes such as dermal absorption.
Cited by
- context BPA is cleared and excreted by the human body within approximately 6 hours under normal conditions.