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Dear All,
1) Can anyone suggest the procedure for performing Whole Blood Stability of analyte after collection
without a anti-coagulant since the analyte to be measured is in Serum.
2) The Analyte to measure in Serum is Endogenous, is it necessary to perform the Selectivity
experiment, if so suggest me a procedure for the same.
Thanks and Regards
S.Mythies Kumar,
PAR Biosciences Pvt Ltd,
Chennai
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Dear S. Mythies Kumar,
Your whole blood stability condition should mimic your serum separation conditions. Like keeping the
blood for ~1 h at room temperature or at 5°C before serum separation. Centrifuge temperature (use
for serum separation) like room temperature or 5°C and time to store serum in deep freezer.
You need to plan your blood stability thinking possible error during clinical phase of the study
(blood collection till serum preparation and storage). You can design whole blood stability based
on clinic condition and types of study you are supporting. Whether the whole blood stability is to
support clinical trials or normal healthy volunteer (NHV) study, will play crucial role designing
this experiment.
Selectivity experiment is a must to do experiment.
I hope this will help you designing your blood stability experiment betterway.
Regards,
Sudipta Basu, Ph.D
Associate Director - Biologics
Dr. Reddy's Lab
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Hi Mythies,
1. Performing whole blood stability without anticoagulant may not be possible.
2. Even for endogenous molecules selectivity need to be performed. Preparing blank matrix by
charcoal stripping is one of the possible option.
3. If the charcoal stripping is not working, surrogate matrix can be used for CC and QC can be
prepared with matrix. These QCs should be back calculated with CC and mean conc of analyte in
unspiked matrix to be added to back calculated conc of QC. Acceptance criteria of these QCs remains
regular one.
Thanks & Regards,
Pavan Kumar Prathipati, M.Pharm
Associate Scientist
Vanta Bioscience.
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Dear Kumar,
Since the compound is present endogenously and you need to quantify compound from the serum and not
from the plasma ,In my opinion no need to perform whole blood stability. In this case your blood is
not going to remain as a blood without anticoagulant for more then 5 to 10 minutes.
The whole blood will coagulated in 5 to 10 minutes post collection from subject and hence it can be
explain to regulatory agency.
Even if you want to check stability, the endogenous level in blood should known to you. You can add
the analyte with standard addition procedure and allow the blood to clot. At the end of stability
period stir the clotted blood again and separate the serum. Measure your compound in harvested
serum. Hope this may suffice purpose
Regards,
Bhavesh
Advinus Therapeutics Ltd,
Bangalore
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Dear All,
I tried Charcoal stripping for over night, but even though I could find some traces of the analyte
of interest. So charcoal stripping method was avoided and some literatures suggests that presently
the use of such stripped plasma and surrogate matrix is avoided everywhere since inconsistent
results are observed. So I tried the subtraction method with endogenous plasma where the area ratio
of the Zero standard was subtracted with the standards and QC's. It gave me best results. But to my
understanding for doing analysis by subtraction method, the selectivity parameter is not required
since iam correcting with the area ratio of the blank sample (average of triplicates), its
applicable for subject samples too where the correction can be done with predose samples.
--
Best Regards
S. Mythies Kumar, M.Pharm| Manager - Bioanalytical
Par Biosciences Pvt. Ltd, 5 & 7th Floor, Robert V Chandran Tower, Pallikarani
Tambaram-Velachery Road - 600100, Chennai, Tamilnadu, India
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