Bioequivalence and Bioavailability Forum

Dear Raghup!

As per section 2.1.1.5 Drugs with an important time of onset of effect or rate of absorption:

For drugs for which an early time of onset or rapid rate of absorption is important for therapeutic effects, for example, an analgesic for rapid relief of pain, the following standard should be met, in addition to the requirements listed in Section 2.1 above:
a) The relative mean area under the curve to the time of the maximum concentration of the reference product (AUCReftmax) of the test to reference product should be within 80.0% ‐ 125.0% inclusive.
The AUCReftmax ratio for each subject should be calculated using values for test and reference products obtained with that subject, and not using a central value (mean or median) for the reference product.
This applies to comparative bioavailability (bioequivalence) studies only. Submissions that make a claim of a more rapid onset of effect, compared to that of the reference product, may require additional pharmacokinetic, pharmacodynamic or clinical data.

where AUCReftmax is: The area under the curve, for a test product, to the time of the maximum concentration of the reference product, calculated for each study subject.

If your study is comparative study, and the values are calculated as per guideline, the ratio needs to be within 80-125%. On the otherhand- if test product claims to have more rapid onset of action compared to refence may require PD or clinical data.
Regards,
Dshah