Hi. I am developing an analytical method based on the quantification of mofetil mycophenolate (MMP) and mycophenolic acid (MPA). For this purpose HPLC with a reversed phase stionary phase column (ODS-C18) and a mobile phase based on a typical phosphate buffer solution and acetonitrile, with a high column temperature, is being used. The literature describe some methods were retention times for MPA are always lower than those for MMF. In my method is just different. Firstly appears MMF (Rt - 7.00) and then MPA (Rt - 16.0). Any Idea for this? Why elution order is different for both molecules if I am using same separation mode based on same stationary and mobile phases? Thx.
So! As long as you can meet the quality compliance requirements of the ICH Q2(r1) you shouldn't care. The difference could be due to your void volume, stationary phase, mobile phase, time of day...
Dear Carlos,
how did you confirm the identity of the two drugs? Dou you analyze standard solutions of both drugs separately? I mean, are you sure the identity of the two peaks obtained?
Regrds.
What is your sample matrix and expected concentrations? The analytical method WILL be different between a drug product and plasma!
Christian. I check identity of peaks by processing standard pure solutions of both analytes.
Bruce. Mi sample matrix is a solution of Glucose 5% in pure water. I am working with similar conditions to those described at bibliography. This is not a difference due to reproducibility.
Carlos,
Could be. In any case send me your e-mail and I will send you the information I have.
Hi John. Final pH of mobile phase os about 3.00 +- 0.10. When I developed the method i tried different mobile phases from bibliography and 3 authors developed his methods with this pH.
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Column