Table 2.
Pharmacokinetic parameters for total and free d6-BPA in serum and urine of human subjects administered d6-BPA via 12-hour dermal application.
| Serum |
Urine |
|||||
|---|---|---|---|---|---|---|
| Cmax (nM) | % free Cmax | AUC0−∞ (nM × h) | % free AUC | t1/2 (h) | Cumulative excreted (μg/kg BW) | |
| 2017 protocol | ||||||
| Total d6-BPA | 2.63 ± 1.69 (5) | 9.66 ± 3.39 (3) | 72.4 ± 45.7 (4) | 8.41 ± 1.67 (2) | 20.0 ± 6.84 (4) | 1.16 ± 0.572 (4) |
| Free d6-BPA | 0.282 ± 0.0583 (3) | – | 8.68 ± 1.35 (2) | – | 12.2 ± 5.16 (2) | – |
| 2014 protocol | ||||||
| Total d6-BPA | 3.66 ± 2.65 (8) | 11.9 ± 4.15 (4) | 107 ± 57.4 (8) | 9.02 ± 1.85(4) | 22.1 ± 11.4 (8) | 0.919 ± 0.554 (8) |
| Free d6-BPA | 0.265 ± 0.193 (4) | – | 6.93 ± 3.18 (4) | – | 20.3 ± 7.77 (4) | – |
| Combined | ||||||
| Total d6-BPA | 3.26 ± 2.31 (13) | 10.9 ± 3.73 (7) | 95.6 ± 54.4 (12) | 8.81 ± 1.65 (6) | 21.4 ± 9.81 (12) | 0.998 ± 0.546 (12) |
| Free d6-BPA | 0.272 ± 0.141 (7) | – | 7.51 ± 2.69 (6) | – | 17.6 ± 7.69 (6) | – |
All values shown as mean ± SD (n), where n is the number of datasets used to estimate the parameter. AUC0−∞ Estimated by log-linear trapezoidal rule from time zero to infinity (using t1/2 and the final serum concentration). Cmax was directly obtained from the data for all datasets. t1/2 estimated for individuals I and G of the 2014 protocol omitted data for t = 12 h, since concentrations increased to t = 24 h. AUC, t1/2 and cumulative amount excreted could not be estimated for individual D due to early withdrawal from the study. Time to Cmax (i.e., tmax) is not applicable because serum concentration increases to Cmax during exposure, and predictably declines when exposure is stopped at 720 min. There was no discernable difference between vehicles (CMC or ethanol) given the interindividual variability, and data for free d6-BPA were only analyzed for the ethanol results. A pilot analysis was performed on the 2014 CMC data, which included an estimate of free d6-BPA (Supplemental Materials Part B-3). These preliminary results are not incorporated in this analysis due to inter-laboratory differences. Results separated by vehicle are available in Supplemental B-1 Table S1.