HPC Tier Module
PBPK Multi-Compartment Pharmacokinetics
Whole-body perfusion-limited PBPK by RK4 - mass-balance and one-compartment anchored, in-browser.
See it run - a worked example, 100% in this browser tab
The problem
Physiologically-based PK modeling of drug disposition across organs usually means installing a solver and trusting an opaque pipeline, with little visibility into the numerical error of the integration.
The local-first solution
This plugin integrates a cited well-stirred PBPK ODE system by classical RK4 entirely in your browser, anchoring results to closed-form mass-balance and one-compartment benchmarks with GeoNum conditioning, and nothing uploaded to anyone's cloud.
What it does
Eight-compartment well-stirred model: arterial, venous, lung, liver, kidney, muscle, fat, rest
Perfusion-limited tissue ODEs with partition coefficients K_p and blood flows Q
Hepatic and renal clearance acting on the effluent venous concentration
Classical RK4 integration of the full state vector with O(dt^4) global error
Mass-balance check (drug plus cleared = dose) and one-compartment IV-bolus benchmark
Cited ICRP 89 / Brown 1997 reference-human flows and volumes echoed as used
Honest scope
Exact are the perfusion-limited ODE system, the RK4 integrator, the mass-conservation identity, and the one-compartment closed form, with error versus benchmark shown. Modeling assumptions include perfusion-limited well-stirred tissues, linear concentration-independent clearance, and a single IV-bolus input; oral absorption, enterohepatic recirculation, active transport, metabolite kinetics, saturable metabolism, and population variability are not modeled. Research and education tool only, not for clinical, diagnostic, dosing, or treatment decisions.
Authorities cited
- Rowland, M., & Tozer, T. N. (2011). Clinical Pharmacokinetics and Pharmacodynamics: Concepts and Applications, 4th ed. Lippincott Williams & Wilkins. - well-stirred organ clearance, perfusion-limited tissue distribution, partition coefficient K_p, recirculating PBPK structure.
- Gibaldi, M., & Perrier, D. (1982). Pharmacokinetics, 2nd ed. Marcel Dekker. - the one-compartment IV-bolus model C(t) = C0 exp(-(CL/V) t), elimination rate constant k = CL/V, half-life t_1/2 = ln2/k (the closed-form benchmark).
- Jones, H. M., & Rowland-Yeo, K. (2013). Basic concepts in physiologically based pharmacokinetic modeling in drug discovery and development. CPT: Pharmacometrics & Systems Pharmacology 2, e63. DOI 10.1038/psp.2013.41. - whole-body PBPK mass-balance ODEs, perfusion-limited assumption, blood-flow connectivity.
- Brown, R. P., Delp, M. D., Lindstedt, S. L., Rhomberg, L. R., & Beliles, R. P. (1997). Physiological parameter values for physiologically based pharmacokinetic models. Toxicology and Industrial Health 13(4), 407-484. DOI 10.1177/074823379701300401. - reference organ blood flows and tissue volumes (the surfaced defaults).
- ICRP Publication 89 (2002). Basic Anatomical and Physiological Data for Use in Radiological Protection: Reference Values. Annals of the ICRP 32(3-4). - reference-adult organ volumes and blood volumes (the surfaced defaults).
- Press, W. H., Teukolsky, S. A., Vetterling, W. T., & Flannery, B. P. (2007). Numerical Recipes, 3rd ed., Sec. 17.1. Cambridge Univ. Press. - classical fourth-order Runge-Kutta (RK4), global error O(h^4); Richardson extrapolation (Sec. 17.3).
Solve the PBPK model
Set the physiology and drug parameters and watch the organ curves with a trust verdict in the browser - nothing is uploaded. Route the run to a Sandbox workspace, a Worklog case, or a Gate client portal.