bioavailabilty in pharmacokinetics

Ratio of the systemic exposure from extravascular (ev) exposure to that following intravenous (iv) exposure as described by the equation:

$F = A ev D iv B iv D ev$

where $F$ is the bioavailabilty, $A$ and $B$ are areas under the (plasma) concentration-time curve following extravascular and intravenous administration, respectively, and $D ev$ and $D iv$ are the administered extravascular and intravenous doses.

Source:

PAC, 2004, 76, 1033 (Glossary of terms used in toxicokinetics (IUPAC Recommendations 2003)) on page 1041