Use this pharmacokinetic calculation when dose, exposure, concentration, time, and route use compatible units and refer to the same analyte and study period.

Dose

A finite measured or assumed value, expressed in mg.

Plasma AUC

A finite measured or assumed value, expressed in mg·h/L.

The implementation follows this calculation rule: Compute drug clearance from an administered dose and the plasma AUC.

Clearance

The calculated clearance in L/h.

AUC segments, clearance, bioavailability, bioequivalence ratios, and concentration–response parameters depend on sampling design and model assumptions. Sparse sampling, extrapolation, nonlinear kinetics, active metabolites, and unaligned doses can invalidate a comparison. Preserve the input values and units so the result can be audited and recalculated.

Inspect the concentration–time data and calculate uncertainty with an appropriate pharmacokinetic model. Peak concentration, time to peak, terminal half-life, and dose-normalized exposure often provide complementary information.

• Steady-State Concentration

  Predict the average plasma concentration at steady state as the infusion rate times bioavailability divided by clearance.

• Apparent Vd

  Estimate volume of distribution as the systemically available dose (administered dose times bioavailability) divided by plasma concentration.

• Bioavailability %

  Compute oral bioavailability as a percentage from AUC and dose comparisons.