Bioequivalence and Bioavailability Forum

Hi All,

I am a fresher in this field.

During processing of plasma samples should we add the internal standard (IS) followed by the analyte in plasma or add analyte in plasma followed by IS.
Since if IS is added first the chances of missing a vial (i.e not adding IS to a vial in between) can be avoided. Most of the methods state addition of analyte in plasma followed by addition of IS.
Is there any guideline to indicate the same.
R we supposed to prove the same during robustness experiment?

Thanks and Regards,

Roshini Singh