Bioequivalence and Bioavailability Forum

Dear Ohlbe,

❝ Which is actually incorrect: you should compare with samples spiked post-extraction, not with unextracted standards. Otherwise in LC-MS/MS methods what you will calculate is a mix of recovery and matrix effects, not just recovery.

The unextractd standard is drug solution. Right ? Comparing the response of sample after extraction and unextracted standard which is drug solution of same concentration. Do you mean instead of using drug solution, we should compare with sample spiked post-extraction. Kindly elaborate.

What about samples that do not go through extraction step ? Plasma samples treated with just the addition of ACN or methanol before injecting into LCMSMS.
We have been doing recovery for sample treated in this way. Is it necessary to have recovery ? We also compare the response of treated sample and drug solution (untreated sample) having similar concentration.

Appreciate your comment.

Thank you.

Regards,
Ken