VP
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2009-10-14 11:10
(5280 d 01:03 ago)

Posting: # 4350
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 drug concentration nil in both periods [Study As­sess­ment]

Dear All

we have conducted one BA/BE study, in which dosing procedure was followed as per protocol. But in bioanalytical analysis for one subject drug concentration was nil for both periods. we excluded that subject from stastical analysis.
How to report same in integrated (clinical) report?

Regards
Vidya


Edit: Category changed. [Helmut]
Helmut
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Vienna, Austria,
2009-10-14 15:51
(5279 d 20:22 ago)

@ VP
Posting: # 4355
Views: 3,850
 

 drug concentration <LLOQ in both periods

Dear Vidya!

❝ [...] for one subject drug concentration was nil for both periods.


Do you mean <LLOQ?
'Nil' doesn't exist in bioanalytics. :-D

❝ we excluded that subject from stastical analysis.


Sure, what's AUCT/AUCR = 0/0...

❝ How to report same in integrated (clinical) report?


As is. But: try to find an explanation anyhow. Is the drug subjected to polymorphic metabolism? One example is codeine, where besides slow/fast metabolizers there is a rare subpopulation of ultrafast metabolizers. In such a case you simply don't catch the parent with an analytical method validated for a BE-study...

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VP
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2009-10-15 14:35
(5278 d 21:38 ago)

@ Helmut
Posting: # 4359
Views: 3,701
 

 drug concentration <LLOQ in both periods

Dear Vienna,

Thanks for the reply.

Drug was Flurbiprofen, as far as I know it doesn't have other active metabolite.
During analysis, for rest of the subjects concentration were detected except one where the concentration was nil for both the periods.

But my confusion is that as subject was dosed but concentration is nil, what will be the possible reason and how to report the same.


regards
VP
SDavis
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2009-10-15 15:18
(5278 d 20:55 ago)

@ VP
Posting: # 4360
Views: 3,790
 

 drug concentration <LLOQ in both periods

Dear Vidya,

I'm sorry to say but if all your other volunteers were easily quantifiable and only this one subject shows no quantifiable values even at Cmax - I have to suspect the possibility that this volunteer did not take his dose in either period...

What is the range from LoQ to Cmax in the other subjects?
Can you confirm that compliance was maintained with oral cavity inspection etc.?

❝ But my confusion is that as subject was dosed but concentration is nil,

❝ what will be the possible reason and how to report the same.


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Helmut
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2009-10-15 15:55
(5278 d 20:18 ago)

@ VP
Posting: # 4362
Views: 3,763
 

 drug concentration <LLOQ in both periods

Dear Vidya!

❝ Dear Vienna,


Funny. My name is Helmut (see my signature and my profile); Vienna is the town I'm living in.

❝ Drug was Flurbiprofen, as far as I know it doesn't have other active

❝ metabolite.


I didn't talk about active metabolites, but metabolism in general. Flurbiprofen is hydroxilated by CYP2C9; polymorphism is documented. Maybe the subject was depressed staying at the clinical site and took St. John's wort (an inducer of CYP2C9). :-D

❝ During analysis, for rest of the subjects concentration were detected

❝ except one where the concentration was nil for both the periods.


Again: please delete 'nil' from your (bioanalytical) vocabulary.

❝ But my confusion is that as subject was dosed but concentration is nil,

❝ what will be the possible reason and how to report the same.


Simon's answer is reasonable. Some volunteers are quite good in hiding a drug during a 'mouth check'. Was this a 'new' volunteer or had you a similar experience with him/her in previous studies?
Concerning reporting: As already said, report the finding as it is. Of course nothing to calculate...

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2009-10-15 16:13
(5278 d 20:00 ago)

@ Helmut
Posting: # 4363
Views: 3,598
 

 drug concentration <LLOQ in both periods

Dear Helmut,

Thanks for your reply. The subject was new, first time enrolled in our CRO. Mouth check was done properly as per our SOP though this incidence happened.

Sorry for writing your name wrong. Hope you won't mind.

Thanks and regards
VP
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