Bioequivalence and Bioavailability Forum

Dear auditor!

❝ Calibration range is: 50 to 1200 ng/ ml

❝ ULOQ QC concentration is: 1215 ng/ ml.

❝

❝ I have object for such kind of estimation of ULOQ QC as it is not within the established CC range under which P&A samples were analyzed.

Agree – that’s really a bad procedure.
Hypothetical situation: accuracy 100%, (im)precision 0% (aka the ‘perfect assay’). High QCs will get back-calculated concentrations > ULOQ = cannot be evaluated = (all!) batches fail.

❝ I need your suggestion regarding this and if possible can you please suggest me any guideline containing such kind of references.

Regulations:

• FDA (2001): The QC samples in duplicate at three concentrations (one near the LLOQ (i.e., ≤3 × LLOQ), one in midrange, and one close to the high end of the range) should be incorporated in each assay run.
  
• EMA (2011): Within- run accuracy should be determined by analysing in a single run a minimum of 5 samples per level at a minimum of 4 concentration levels which are covering the calibration curve range: the LLOQ, within three times the LLOQ (low QC), around 50% of the calibration curve range (medium QC), and at least at 75% of the upper calibration curve range (high QC).

FDA’s “close to the high end” does not mean “above”. EMA’s deals with pre-study method validation; in the rest of the text only low-medium-high is stated. IMHO ≥75% of the ULOQ makes a lot more sense than close to the ULOQ. Remember that acceptable inaccuracy is ±15%; if the CRO places the high QC too close to the ULOQ chances are high (±15% CV!) that at least one of the QCs will be rejected by pure chance.

❝ I have referred the entire available article pertinent to this but I could not get any information for the same.

Do you mean the “Arlington III whitepaper”?

Viswanathan CT, Bansal S, Booth B, DeStefano AJ, Rose MJ, Sailstad J, Shah VP, Skelly JP, Swann PG, and R Weiner
Workshop/Conference Report – Quantitative Bioanalytical Methods Validation and Implementation: Best Practices for Chromatographic and Ligand Binding Assays
The AAPS Journal 9(1), E30-E41 (2007)
online resource

Nothing specific is stated concerning chromatographic methods: ‘High: near the high end of range’. That’s FDA’s. I would follow EMA’s suggestions for the reasons given above.