Recovery Issues and Compensating For Them

[danko]

If the folic acid is not recovered/available following the chromatographic run, then what would be the argument for assuming that it’ll be available following administration (orally or injected or whatever) thus correcting the value with a factor?

If I were to justify such a procedure, I’d need to explain what happened to the part that wasn’t eluted or detected or whatever – at least.

Best Regards

[cody84]

I would suggest tracking down exactly what's going on and proving it. I dunno I think as long as you can provide evidence they should accept it, not sure how it works in reality though.

[R13]

I do not think that the main compound assay can be adjusted using factor.
It is not enough to know that recovery is 90 %. To use re-calculation factor You should have good knowledege WHY this is happening and prove that there is no other way to measure it.

The main question is (since validated method will be "approved" by some autority)- what are regulatory documents saying about this. I suspect there is some document direcly forbiding/regulating this. It is more QA/regulatory question rather than chromatography.

[R13]

This is exactly the issue which can be questioned in the validated method review:
- You measure, calculate assay using factor - and result fails the limits for assay. Does it mean amount of the analyte in product is wrong or is it because amount of interfering compound is different? You have two possibilities here and that is not acceptable.