Bioequivalence and Bioavailability Forum

IS carry-over? [Bioanalytics]

posted by Helmut  – Vienna, Austria, 2014-11-21 17:45 (4236 d 17:06 ago) – Posting: # 13909
Views: 16,403

Merhaba Emrah!

❝ It is reported as "Fault in the sample processing".

OK, but how can you know that? Was anything documented in the lab journal like “I’m not sure whether I added the IS to this sample”? Can you give us:

• The LLOQ and ULOQ of the method.
  
• The concentration of samples analyzed in the batch before and after the doubt­ful value.
  
• The concentration of samples of the subject’s profile before and after the doubt­ful value + their sampling time points.
  
• The ranges of C_max-values in the study.

❝ ❝ Conc: 418.78

❝ ❝ Re-analysis 1: 8.76

❝ ❝ Re-analysis 2: 7.24

❝ ❝ Means of Reanalyses : 8.00

❝ ❝ Reported Conc: NR

NR because “duplicate repeats were more than 20 percent different from one another”. That’s a matter of perspective:

Re-analysis 1: 8.76 (+21.0% of 7.24, –9.5% of x)
Re-analysis 2: 7.24 (–19.9% of 8.76, +9.5% of x)

Obviously the decision to not report the value was based on the first replicate – why not on the second? Looks like an ambiguity in the SOP.
If ever possible (i.e., suf­fi­cient sample) run triplicates and use the median for assess­ment.

In which country do you want to submit the study? Bad luck for the EU and seemingly for Turkey as well.
However, I would explore potential impact of IS carry-over. Inject a sample spiked to a similar concentration like the sample in the batch before the doubtful value followed by a spiked sample without IS.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


The quality of responses received is directly proportional to the quality of the question asked. 🚮
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Complete thread:

• Handling "Not Reportable" Data Emrah Soner Özdeş 2014-11-21 07:25 
  • Handling "Not Reportable" Data ElMaestro 2014-11-21 07:34
    • Handling "Not Reportable" Data Emrah Soner Özdeş 2014-11-21 07:54
      • Handling "Not Reportable" Data nobody 2014-11-21 08:07
        • Handling "Not Reportable" Data Emrah Soner Özdeş 2014-11-21 08:18
          • Handling "Not Reportable" Data ElMaestro 2014-11-21 09:53
          • Handling "Not Reportable" Data nobody 2014-11-21 11:11
            • Handling "Not Reportable" Data Emrah Soner Özdeş 2014-11-21 16:14
              • IS carry-over?Helmut 2014-11-21 16:45
                • IS carry-over? nobody 2014-11-21 17:19
                • IS carry-over? Emrah Soner Özdeş 2014-11-24 08:58
                • IS carry-over? Emrah Soner Özdeş 2014-11-27 10:28
                  • Another story! Helmut 2014-11-27 14:21
                    • Another story! Emrah Soner Özdeş 2014-11-28 10:00
                    • Another story! nobody 2014-11-28 10:18
      • Handling "Not Reportable" Data AngusMcLean 2014-11-28 19:09
        • EMA and similar regulations… Helmut 2014-11-28 19:16
          • EMA and similar regulations… jag009 2014-12-01 19:54