RAPID COMPARTMENT-INDEPENDENT AND MODEL-INDEPENDENT ESTIMATION OF TIMES REQUIRED TO ATTAIN VARIOUS FRACTIONS OF STEADY-STATE PLASMA-LEVEL DURING MULTIPLE DOSING OF DRUGS OBEYING SUPERPOSITION PRINCIPLE AND HAVING VARIOUS ABSORPTION OR INFUSION KINETICS

A new general equation based only on plasma data was derived for rapid estimation of the average plasma level and the mean fraction of the steady‐state plasma level attained during any multiple‐dosing interval. It can be applied to any complex absorption or infusion kinetics (i.e., is not limited to zero‐order or first‐order kinetics) for drugs obeying linear disposition kinetic or superposition principles. The time, t, required to reach a certain mean fraction of the steady‐state plasma level is equal to the time at which the plasma area from time zero to time t is equal to the same fraction of the plasma area from time zero to infinity (AUC0→ ∞) following a single dose. No other pharmacokinetic parameters are necessary. Copyright © 1979 Wiley‐Liss, Inc., A Wiley Company