deepakpangavhane
☆    

India,
2018-09-03 10:28
(2291 d 05:05 ago)

Posting: # 19205
Views: 5,903
 

 recoveries more than 100% [Bioanalytics]

Hi everyone!

The % recovery was 107.80%, 112.65% and 105.92% for the low quality control (LQC) and middle quality controls (MQC2 and MQC1), respectively. Whereas % recovery for higher quality control (HQC) was 98.25%.

The % recovery was determined by comparing the mean peak area of 6 replicates of extracted quality control samples at High, Middle and Low concentrations against respective mean peak area of 6 replicates of un-extracted quality control samples at High, Middle and Low concentrations. Internal standard used was deuterated.

Kindly confirm recoveries markedly higher than 100% for LQC, MQC2 and MQC1 are acceptable as per USFDA guidelines?? Also specify reason for higher recoveries.
Ohlbe
★★★

France,
2018-09-03 21:21
(2290 d 18:13 ago)

@ deepakpangavhane
Posting: # 19231
Views: 5,174
 

 recoveries more than 100%

Dear Deepak,

❝ The % recovery was determined by comparing the mean peak area of 6 replicates of extracted quality control samples at High, Middle and Low concentrations against respective mean peak area of 6 replicates of un-extracted quality control samples at High, Middle and Low concentrations.


Meaning that what you observe is a mix of extraction recovery and matrix effect. If you want to see the true extraction recovery you have to compare to samples spiked post-extraction. You can combine with matrix effects experiments.

❝ Internal standard used was deuterated.


Makes no difference. You are looking at peak areas, not peak area ratios.

❝ Kindly confirm recoveries markedly higher than 100% for LQC, MQC2 and MQC1 are acceptable as per USFDA guidelines??


Did you see any limit for absolute recovery in either direction in the FDA guidance ?

❝ Also specify reason for higher recoveries.


Multiple. The most probable: analytical variability (your results are well within the 15 % acceptance limits for precision and accuracy). Other possibilities include ion enhancement, sample preparation, calculation errors...

Regards
Ohlbe
Ladi
☆    

Thailand,
2018-09-04 05:51
(2290 d 09:43 ago)

@ deepakpangavhane
Posting: # 19232
Views: 5,088
 

 recoveries more than 100%

Hello Deepak and Ohlbe,

❝ The % recovery was 107.80%, 112.65% and 105.92% for the low quality control (LQC) and middle quality controls (MQC2 and MQC1), respectively. Whereas % recovery for higher quality control (HQC) was 98.25%.


My lab called the 'post-extraction' as 'un-extracted', I am guessing you also mean that?

I observed recovery 100-115% mostly with protein precipitation projects in our lab. My explanation to auditors was that the extracted samples are little bit more concentrated than the post-extracted samples because some protein is precipitated out in extracted samples. While in the post-extracted samples, the measured volume of supernatant from precipitated blank is use to make up a required concentration. Ususally for protein precipitation, recovery is almost 100%. So if extracted is more concentrated than it supposed to be (expected conc.), recovery may cross 100%. However, I normally see similar %recovery across all concentrations.

Regards,
Ladi
Kintan Patel
☆    

India,
2018-11-29 12:48
(2204 d 01:45 ago)

@ Ladi
Posting: # 19659
Views: 4,713
 

 recoveries more than 100%

Hello Ladi and Deepak,

The % recovery across all concentration levels (i.e LOW ,MED add High) should be consistent that means %CV should be within 20% across all levels and also you should mentioned the accepted % recovery range (i.e from 30% to 120%) in your SOP and this high % recovery might be due to ion enhancement , sample preparation error etc. and also it is acceptable as per FDA guideline.(limit for % recovery is not mentioned in FDA Guideline)

Thank You,
Kintan Patel


Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe]
Ohlbe
★★★

France,
2018-11-30 19:23
(2202 d 19:11 ago)

@ Kintan Patel
Posting: # 19665
Views: 4,738
 

 Origin of figures ?

Dear Kintan Patel,

❝ The % recovery across all concentration levels (i.e LOW ,MED add High) should be consistent that means %CV should be within 20% across all levels


Could you clarify where you took this value of 20 % from ?

❝ and also you should mentioned the accepted % recovery range (i.e from 30% to 120%) in your SOP


Why 30% to 120% ? Where do these values come from ?

Regards
Ohlbe
Kintan Patel
☆    

India,
2018-12-05 11:04
(2198 d 03:29 ago)

@ Ohlbe
Posting: # 19668
Views: 4,682
 

 Origin of figures ?

Dear Ohlbe,

❝ ❝ The % recovery across all concentration levels (i.e LOW ,MED add High) should be consistent that means %CV should be within 20% across all levels


%CV for % recoveries across Low, med and high level shall be within 20 %.

❝ Why 30% to 120% ? Where do these values come from ?


This is just example. You can keep accepted % recovery as 25 % to 125 % etc. in you SOP,but in guideline % recovery criteria no where mentioned but many industries had included acceptance criteria of % recovery in their SOP.

Thanks ,
Kintan Patel


Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe]
Ohlbe
★★★

France,
2018-12-05 11:30
(2198 d 03:03 ago)

@ Kintan Patel
Posting: # 19669
Views: 4,603
 

 Origin of figures ?

Dear Kintan Patel,

❝ %CV for % recoveries across Low, med and high level shall be within 20 %.


Why 20 % ? Where did you take that value from (apart from your own SOP) ?
How do you calculate the CV: take all individual values ? Or the average at L, average at M and average at H level ?

❝ ❝ Why 30% to 120% ? Where do these values come from ?


❝ This is just example. You can keep accepted % recovery as 25 % to 125 % etc. in you SOP [...]


Right. Then e.g., not i.e.

Regards
Ohlbe
UA Flag
Activity
 Admin contact
23,336 posts in 4,902 threads, 1,666 registered users;
33 visitors (0 registered, 33 guests [including 9 identified bots]).
Forum time: 14:34 CET (Europe/Vienna)

I’m all in favor of the democratic principle
that one idiot is as good as one genius, but I draw the line
when someone takes the next step and concludes
that two idiots are better than one genius.    Leo Szilard

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5