Bioequivalence and Bioavailability Forum

Dear Ramesh!

❝ Canadian guidelines (Part-A sec 6.9)...

❝ I want to know the methodology adopted for the blinding of the QC's

❝ samples during the samples analysis.

First a remark: Canada is the only country I know calling for blinded QC's...

The procedure is pretty straightforward - if you have at least two analysts in your lab. The first one is preparing the CCs and performing the actual analyses, whereas the second one is preparing the QCs. QCs must be labelled in a neutral manner (like QCa, QCb, QCb - where a, b, c does not refer to the concentration level - like a < b < c).
For every set of QCs (used in the analytical batches) the order must be different, because after the first analytical run the analyst is unblinded due to the response (he simply knows e.g., b < c < a)...
The analyst has to turn his attention on instrument carry-over, i.e., inject a blank sample prior and after any QC in order to avoid bias due to carry-over (most spec's of autosamplers are <0.5%).

If there's only one analyst in the lab, he/she must prove during an inspection his/her short memory-span...
Another possibility would be to label QCs with a random code which is opened after each run.