ACIDS LIKE TARTARIC ACID ETC.

[N.V.V.S.S. RAMAN]

Dear Friends,

When I developing methods for salts like fumerate, tartrate, maleate of some drugs, I am getting problem of these salts. They elute at below 2 min and getting merged with blank . To avoid this blank intereference is very difficult. Whatever mobile phase and whatever column may be , the problem is persisted. Can anybody suggested a solution

Regards,
raman

[zompa]

Hi Raman,

I don't know if it could be helpful to you but everytime I analyse such compounds I use the ionic chromatograph... it works!

[ym3142]

google.

[N.V.V.S.S. RAMAN]

Thank you Zompa

But in our case, while analysing the drug this salt will also respond at a lower level. So we are asked to address and quantify the same at this level. That is the reason we are struggling.

Raman

[Uwe Neue]

I assume that you have developed methods already for content uniformity, impurity profile and degradation products of the parent drug. If this is the case, the simplest method is to develop a separate method for the counterions, maybe with ion-pair chromatography or ion chromatography, and then use this method as a generic method for the counterions.

Is this acceptable?

[zompa]

Ok,

What Uwe suggested is what we do ordinarily when we analise such drugs.
We have separate methods for the counter-ions and for the "base".
So we "off-integrate" the peak of the anion while testing the counterpart purity.
bye.