Validation issues arising from the new FDA guidance for industry on bioanalytical method validation

In late May 2001 the FDA issued their final Guidance for Industry on Bioanalytical Methods Validation. Different types and levels of validation, dependent on the status or changes to the validated method, are now defined and characterised. Additional experiments with the emphasis on the newer hyphenated analytical techniques and changes to quality control and calibration acceptance criteria are now required. A number of inconsistencies, in terms of the minimum number of calibration points required to define a calibration curve, exist in the current document. It is therefore important to understand the underlying philosophy of this guidance and what are the most appropriate ways of implementing this philosophy.