in pharmacokinetics
Ratio of the systemic exposure from extravascular (ev) exposure to that following intravenous (iv) exposure as described by the equation: \[F=\frac{A_{\text{ev}}\ D_{\text{iv}}}{B_{\text{iv}}\ D_{\text{ev}}}\] where F is the bioavailabilty, A and B are areas under the (plasma) concentration-time curve following extravascular and intravenous administration, respectively, and Dev and Div are the administered extravascular and intravenous doses.
PAC, 2004, 76, 1033. 'Glossary of terms used in toxicokinetics (IUPAC Recommendations 2003)' on page 1041 (