Pharmacology & Dosage
Intermediate

Bioavailability

Fraction of an oral dose that reaches systemic circulation compared with an IV dose.

Formula

F=AUCoralAUCIV×100F = \frac{AUC_{oral}}{AUC_{IV}} \times 100

Live Calculator

Members

Variables

FBioavailability (%)
AUC_{oral}Area under the curve for oral route
AUC_{IV}Area under the curve for IV route

Example

AUCoral = 80, AUCIV = 100 → F = 80 %

Did You Know?

IV drugs have 100 % bioavailability by definition — they skip the gut and liver first-pass effect entirely.

pharmacologybioavailabilityoralabsorption

Share this formula

More in Pharmacology & Dosage

View all

Drug Half-Life

Intermediate

Time for the plasma concentration of a drug to fall to half its initial value.

Steady-State Concentration

Intermediate

Average plasma drug concentration when intake and elimination are balanced.

Loading Dose

Intermediate

Initial higher dose to rapidly achieve the desired plasma concentration.

Maintenance Dose

Intermediate

Recurring dose needed to sustain the steady-state concentration.

Volume of Distribution

Basic

Apparent volume into which a drug distributes — a larger Vd means the drug leaves the bloodstream and enters tissues.

Clearance

Intermediate

Volume of plasma completely cleared of a drug per unit time.