Pro Tier Module
Pharmacokinetic Half-Life & Clearance Calculator
Linear PK half-life, clearance, and AUC - exact closed forms plus drift-tracked trapezoidal AUC, in-browser.
This tool runs inside GDBS Pro. What it computes and the authorities it applies are below.
The problem
Clinical-PK and bioequivalence work needs half-life, clearance, and AUC from both closed-form models and sampled concentration-time curves, where the trapezoidal AUC summation spans orders of magnitude and float conditioning is hard to judge.
The local-first solution
This plugin computes the exact linear-PK identities and a linear or log-trapezoidal AUC entirely in your browser, re-running the AUC summation through the real GeoNum kernel to report how trustworthy that accumulation is.
What it does
One-compartment IV bolus: C0, ke and t1/2, CL = ke * Vd, analytic AUC = C0 / ke
Two-compartment bi-exponential disposition with AUC = A/alpha + B/beta and terminal t1/2
Numeric AUC by linear and hybrid linear-up / log-down trapezoidal rules
Tail extrapolation C_last / lambda_z from AUC_last to AUC_inf
Numeric-vs-analytic AUC residual reported to quadrature error
GeoNum drift verdict on the AUC summation as a conditioning signal
Honest scope
Exact closed forms are C0, ke and t1/2, CL = ke*Vd, and the analytic AUC; the trapezoidal AUC is a quadrature whose residual versus analytic is reported and whose conditioning GeoNum probes (a signal, not extra precision). First-order absorption, nonlinear or Michaelis-Menten elimination, multiple dosing, protein binding, and inter-individual variability are flagged, not computed - this is single-dose linear IV-bolus PK only. Not medical or dosing advice.
Authorities cited
- Gibaldi, M. & Perrier, D. (1982). Pharmacokinetics, 2nd ed. Marcel Dekker. - One- and two-compartment IV-bolus disposition; C(t)=C0 e^-ke t, t1/2 = ln2/ke, AUC_0_inf = C0/ke; bi-exponential C(t)=A e^-alpha t + B e^-beta t with AUC = A/alpha + B/beta.
- Rowland, M. & Tozer, T. N. (2011). Clinical Pharmacokinetics and Pharmacodynamics: Concepts and Applications, 4th ed. Lippincott Williams & Wilkins. - Clearance CL = ke*Vd = Dose/AUC; volume of distribution; half-life relationships.
- Gabrielsson, J. & Weiner, D. (2016). Pharmacokinetic and Pharmacodynamic Data Analysis, 5th ed. Apotekarsocieteten. - Non-compartmental analysis; linear-up / log-down trapezoidal AUC; C_last/lambda_z tail extrapolation to AUC_0_inf.
- Chiou, W. L. (1978). Critical evaluation of the potential error in pharmacokinetic studies of using the linear trapezoidal rule method for the calculation of the area under the plasma level-time curve. J. Pharmacokinet. Biopharm. 6(6), 539-546. - The log-trapezoidal (log-down) rule for declining segments.
- U.S. FDA (2001/2022). Guidance for Industry: Bioavailability and Bioequivalence Studies / Statistical Approaches to Establishing Bioequivalence. - AUC_0_t, AUC_0_inf, lambda_z extrapolation as the bioequivalence exposure metrics.
- Higham, N. J. (2002). Accuracy and Stability of Numerical Algorithms, 2nd ed. SIAM. DOI 10.1137/1.9780898718027. - Conditioning of accumulating summation (the GeoNum drift probe on the AUC sum).
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Run the PK math
Enter dose and parameters or a sampled curve and read half-life, clearance, and AUC with a trust verdict in the browser - nothing is uploaded. Send it to a Sandbox workspace, a Worklog case, or a Gate client portal.