TABLE 3.
Population pharmacokinetic parameter estimates for l- and d-eflornithine after oral administration of racemic eflornithinea
| Parameter | l-Eflornithine estimate (RSE) | Value for R-eflornithine
|
d-Eflornithine estimate (RSE) | |
|---|---|---|---|---|
| Estimate (RSE) | IIV (RSE) | |||
| Tmax (μmol/min/kg of body wt) | 11.1 (17) | 14.5 (10) | ||
| Kt (μmol/kg of body wt) | 1,560 (25) | 784 (28) | ||
| MTT (min) | 88 (12) | 38 (29) | ||
| n | 1.424 (21) | |||
| F (%) at 750 to 2,000 mg/kg of body wt | 41 (6.5) | 10.0 (37) | 62.3 (9.5) | |
| F (%) at 3,000 mg/kg of body wt | 47 (7.5) | 82.7 (7.5) | ||
| Random residual variability (σ) (% coefficient of variation) | 27.7 (18) | |||
a
R-eflornithine represents parameters that were set to be identical for l- and d-eflornithine. CL, Q, and central and peripheral volumes of distribution were fixed to the values obtained in fitting the intravenous data. MTT, mean transit time to the absorption compartment; n, number of transit compartments before reaching the absorption compartment; F, absolute oral bioavailability; IIV, interindividual variability; σ, additive residual error; RSE, relative standard error [(standard error/mean) × 100].