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The following message was posted to: PharmPK
dear all,
1) Is it necessary to perform matrix effect if i m using deutoriated IS.
2) if deutratied IS area varies from 40 to 200% in a batch and all
QC's are passing hving same IS variation. Is it accptable?
ashish saxena
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The following message was posted to: PharmPK
Dear Ashish,
1. Yes, matrix effect experiment is necessary.
2. IS variation should not cross your in-house criteria.
Just check your extraction procedure. If you are sure about your extraction procedure and other processing error, then it's a clear cut matrix effect problem. Try gradient method and better extraction procedure.
Regards,
S.Basu
Sr. Research Scientist
Sai Advantium Pharma Ltd.
Pune, India
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The following message was posted to: PharmPK
Is your IS variation systematic or random? If it is random, there will
be more worry on whole batch analysis. If it is systematic and only
initial time points show low IS, then it is matrix effect. I have seen
this especially when PEG is there in formulation. You can work around
this issue by varying gradient and avoid co-elution of sample and one of
formulation component.
Regards,
Vinayak
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Matrix effect is recommended as a component of validation. You need not do anything but report it, unless the recovery is low and variable for your analyte. Recovery of the analyte can be low but precise and acceptable.
The internal standard should behave similarly to the analyte, but unless you have something restrictive in your SOPs, there are no other fixed requirements for IS recovery. You might specify a minimum and max IS area and IS asymmetry, as well as area ratio.
Do the QCs at a given level show the same variability? Deuterated and other isotopics can interfere with analyte responses and analyte can interfere with the responses of the labeled IS.
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Dear Asish
It will be good to check the matrix effect in order to avoid any problems later in running longer batches.
As suggested by others you can check your in house criteris for the variation limit but this mush variation will not be acceptable by the regulatory agencies.
You can do the following simple expt to confirm the matrix effect:
Inject and run your extracted blank matrix sample through the column using your present method and do the post column infusion of your IS solution simultaneously. If there is no matrix effect you should be getting a consistent base line without any variations throughout the run but if there is any matrix component present in the extract which is causing the matrix effect then you would be able to see a rise in the baseline at the same RT where your IS was eluting . If it confirms the presence of matrix effect you can either work on the extraction procedure or the HPLC method to eliminate this interference. Hope this will help.
Warm Regards
Lakshmikant Bajpai
Chem Biotek, Pune
INDIA
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The following message was posted to: PharmPK
Rise in the baseline at the retention time of IS is caused by matrix effect, called enhancment. If you see a valley at the retention time of IS can also be a matrix effect, called ion supression.
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