Table II.
Parameter Estimates of the Integrated PK Model and Results of the Bootstrap Internal Validation Procedure
| Parameters | Original dataset | Bootstrap datasets (n = 2,000) | ||
|---|---|---|---|---|
| Estimate ± SE | Mean ± SD | Median | 2.5th–97.5th percentiles | |
| Fixed effect parameters | ||||
| K a (AR) (1/min) | 0.0101 ± 0.0020 | 0.0105 ± 0.0305 | 0.00977 | 0.007–0.016 |
| K e (AR) (1/min) | 0 (fixed) | 0 (fixed) | 0 (fixed) | – |
| K e (AG) (1/min) | 0.213 ± 0.019 | 0.215 ± 0.019 | 0.214 | 0.183–0.249 |
| K e (AA) (1/min) | 0.0768 ± 0.0061 | 0.0819 ± 0.0090 | 0.0783 | 0.071–0.095 |
| V (L) | 0.283 ± 0.011 | 0.279 ± 0.011 | 0.278 | 0.258–0.302 |
| K m1 (μmol/L) | 204 (fixed) | 204 (fixed) | 204 (fixed) | – |
| V m1 (μmol/min) | 12.4 (fixed) | 12.4 (fixed) | 12.4 (fixed) | – |
| K m2 (μmol/L) | 13.5 (fixed) | 13.5 (fixed) | 13.5 (fixed) | – |
| V m2 (μmol/min) | 0.292 (fixed) | 0.292 (fixed) | 0.292 (fixed) | – |
| K m3 (μmol/L) | 230 (fixed) | 230 (fixed) | 230 (fixed) | – |
| V m3 (μmol/min) | 1.23 (fixed) | 1.23 (fixed) | 1.23 (fixed) | – |
| SF1 | 0.907 ± 0.272 | 0.885 ± 0.283 | 0.836 | 0.528–1.418 |
| SF2 | 0.874 ± 0.043 | 0.881 ± 0.053 | 0.881 | 0.795–0.967 |
| SF3 | 1.43 ± 0.10 | 1.41 ± 0.10 | 1.41 | 1.249–1.577 |
| F1 | 0.0862 ± 0.0147 | 0.0852 ± 0.0162 | 0.0853 | 0.059–0.112 |
| Prop.RE | 4.37 ± 0.61 | 4.20 ± 0.55 | 4.31 | 3.302–5.057 |
| Add.RE | 0.0849 ± 0.0187 | 0.0906 ± 0.0181 | 0.0859 | 0.067–0.123 |
| Residual | 0.0199 ± 0.0060 | 0.0155 ± 0.0020 | 0.0153 | 0.012–0.019 |
SE standard error, K a absorption rate constant, K e elimination rate constant, V volume of distribution, V m1 , V m2, and V m3 maximum rate of metabolism in intestine, plasma, and liver of arctigenin, respectively, K m1 , K m2 , and K m3 Michaelis constant of metabolism in intestine, plasma, and liver of arctigenin, respectively, SF 1 , SF 2 , and SF 3 scale factor of metabolism in intestine, plasma, and liver of arctigenin, respectively, “–” not available, F1 fraction absorbed, Prop.RE proportional residual error, Add.RE additive residual error