Bioequivalence and Bioavailability Forum

Hello Bert,

❝ Is there any guidance for the location of calibration samples in an analytical run? Should this be at-random? (Like it, called Junior )

There is to the best of my knowledge no guidance that deals explicitly with it.
Sometimes such samples are in the beginning of a run, and often the outcome is monitored so that if something is clearly out of whack the run can be terminated early so as not to lose PK sample material.
Some CROs with rock-solid systems intersperse them rather randomly throughout runs after a few sys suit injections. Others yet have two sets of cals per run, one in the beginning and one in the end.

All variants seem to work fine in terms of regulatory acceptance.

Hi Bert,

❝ Is there any guidance for the location of calibration samples in an analytical run?

Not that I recall. I agree with ElMaestro’s comments.

❝ Should this be at-random?

Not a good idea – even if there is no substantial carry-over (see the EMA’s GL Section 4.2.2). If you decide to inject calibrators at the start and end of the batch do so with increasing concentrations which minimizes the relative impact of carry-over. If you have calibrators within the set of unknown samples inject a blank after. The same is applicable for QC samples as well.

❝ (Like it, called Junior )

Not referring to your age or experience but the number of posts in the forum.
Junior : <25
Regular: 25 < 100
Senior : 100 < 500
Hero   : >500