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The following message was posted to: PharmPK
Dear All,
Can you comment if it is acceptable to adjust few parameters during
samples
analysis of bioequivalence studies,
(using naturally a validated method), such as flow rate? Also, would you
consider a change in the RT (retention time),
during the analytical run an issue?
Thanks,
Avi
Avi Avramoff
V.P., Research & Development
Dexxon Ltd.
Tel: 972-4-6364003
Fax: 972-4-6364004
E-mail: rnd.aaa.dexxon.co.il
Mobile: 972-54-758965
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The following message was posted to: PharmPK
Dear Avi,
Your adjust in a analytical method during a BE study could not affect
your
validated results. If you change the flow rate, consequently, you
change the
RT. So, your RT could not altered more than 1% of the validated values.
Another way, is include this few parameters changes in your validated
method. In my opinian, in this issue, important is the RT of the
validated
method to be equal to the RT of voluntaries samples.
Regards,
Daniel Rossi de Campos
Hi Avi,Back to the Top
Yes, changes in the parameters of the analytical method (such as
flow-rate) require re-validation.
It is possible that the re-validation should not be as extensive as the
initial validation.
The change in the retention time is of concern. This is an indication
that the "process" is not "under control". Meaning that factors outside
those defined initially in the method development influence the outcome
of the assay . Since the specificity of the assay is linked to the
retention time this issue must be elucidated before starting the
analysis of the actual samples.
I hope this helps,
radu
Radu D. Pop
Director Biopharmaceutics
Pharma Medica Research Inc.
966 Pantera Drive
Mississauga, Ontario
Canada, L4W 2S1
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If you use an internal standard you can then generate a retention time
ratio which will be fixed as long as only minor changes in flowrate,
solvents are used.
Validation will need to look at linearity, LLOQ, ULOQ, precision and
accuracy. Stabilities do not need to be revalidated.
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Copyright 1995-2010 David W. A. Bourne (david@boomer.org)