Steady-State Drug Accumulation Simulator (2D)

This 2D companion to the 3D steady-state accumulation simulator models the same real one-compartment oral pharmacokinetics, but computes it a genuinely different way: instead of evaluating the closed-form Bateman equation, it numerically integrates the two-compartment mass-balance ODEs — gut depot absorption and plasma elimination — step by step with 4th-order Runge-Kutta, the way an actual pharmacokinetic simulation engine works under the hood. Each administered dose is injected as an instantaneous bolus into the gut depot, then drains into the plasma compartment at a rate proportional to how much drug remains there, while the plasma compartment simultaneously empties by first-order elimination. Watch the two compartments fill and drain as flowing tanks, and the scrolling concentration trace climb toward its steady-state plateau. Adjust dose, dosing interval, elimination half-life and volume of distribution to see how a regimen's shape changes, and toggle a loading dose to reach the plateau almost immediately instead of after several half-lives.