Dear specialists,
we are currently working on a drug product which contains tetracycline.
So far, it seems that the separation of N-Nitroso-N-Desmethyl Tetracycline impurity form Tetracycline as well as their detection in LC-MS/MS (System: UPLC-ESI(negative)-QQQ) are quite challenging. Co-elution and low signal for both compounds are the main problems that we are facing.
Does anyone have any experience on this analysis and could suggest something?
Thank you in advance!
Christos
Our group has no experience with this compound, but I’ll say what I would do if in your shoes. First, many standard manufacturers are happy to share their methods and it doesn’t hurt to ask. Next, I would begin talking to column manufacturers. @MTwohig from Waters was a great help to us, both in having an excellent discussion & providing a few methods that we used as starting points for our own.
Dear Jason,
first of all thank you for your feedback, it is much appreciated!!
Actually, the method which have been send to us from the API manufacturer was a little bit disappointing as it was developed without the reference standard.
The ref. standard which we have in the lab it is from another vendor and it is a good idea to ask for the method from them.
best regards
Christos