Each test parameter is validated against published textbook reference values.
PASS criteria are based on absolute tolerance
(|Computed − Expected| ≤ Tolerance), calibrated to account for method-dependent
variation commonly observed across validated NCA software platforms.
Observed values (Cmax, Tmax, Clast, Tlast): Strict — near-zero tolerance. Direct read from data.
AUC parameters: ≤0.5–2.0 units. Integration method variation (linear vs. log-linear) accounts for typical ±1% differences.
Terminal phase (λz, t½): ≤0.5–2.0 units. λz regression point selection (Best-fit vs. manual) commonly introduces ±1–5% variation across platforms (Gabrielsson §10.3.2).
Derived parameters (CL/F, Vz/F, Vss/F, MRT): Dose-dependent; tolerance scaled to expected magnitude. Variation propagated from AUCinf and λz estimates.
Quality metrics (R²adj, AUC%extrap): Dimensionless. R²adj ≥0.99 required for reliable λz; AUC%extrap <20% per FDA BE guidance.
Cross-validation: All-linear AUC computed independently to verify log-linear method consistency.
Key References:
[1] Gabrielsson & Weiner, PK/PD Data Analysis, 5th ed., 2016 —
[2] Rowland & Tozer, Clinical Pharmacokinetics, 4th ed., 2011 —
[3] Gibaldi & Perrier, Pharmacokinetics, 2nd ed., 1982 —
[4] Wagner, Fundamentals of Clinical Pharmacokinetics, 1975 —
[5] Zhang et al., PKSolver, Comput Methods Programs Biomed, 2010