Bioequivalence and Bioavailability Forum • Duplicate LLOQ and ULOQ

Duplicate LLOQ and ULOQ [Bioanalytics]

posted by Ohlbe – France, 2012-01-20 12:59 (5269 d 17:26 ago) – Posting: # 7975
Views: 6,174

Dear Auditor,

What most people do is that they only use one of the two replicates of the LLOQ and ULOQ samples. Usually the first replicate is used, unless it fails (> 20 % deviation from nominal at the LLOQ, 15 % at the ULOQ) or there is a clear analytical reason (instrument failure, chromatographic interference). This should be defined in a SOP. Some people take whichever value gives the highest R², but I don't like that (I don't consider R² to be a relevant parameter).

The idea of running the LLOQ and ULOQ samples in duplicate is to avoid having to truncate the curve if one of these samples is failing.

Regards
Ohlbe

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Regards
Ohlbe

Complete thread:

Calibration Curve auditor 2012-01-20 11:15
- Duplicate LLOQ and ULOQOhlbe 2012-01-20 11:59
  - Duplicate LLOQ and ULOQ Helmut 2012-01-20 13:09
    - Duplicate LLOQ and ULOQ Ohlbe 2012-01-20 14:26
      - Duplicate LLOQ and ULOQ Helmut 2012-01-20 18:02
        
        Calibration Curve auditor 2012-01-21 05:45
        
        Calibration Curve Helmut 2012-01-21 12:35
        Calibration Curve Ohlbe 2012-01-21 13:44
        
        Calibration Curve Helmut 2012-01-22 21:48