An overview of the analysis and interpretation of bioavailability studies in man

Bioavailability is defined and types of bioavailability studies are classified. The point is made that the validity or interpretation of comparative bioavailability data does not rest on any correlation between pharmacological or clinical response and blood levels of the drug. Equations used to assess the "first pass" effect, absolute absorption efficiency and relative absorption efficiencies are given. Methods for assessing intrinsic and relative rates of absorption are discussed. Various pitfalls in bioavailability assessment and some of the problems in interpreting bioavailability data are discussed.