How To Test Tofacitinib Citrate By NMR/HPLC?
This post is for all the customers who have ordered tofacitinib citrate API, whether it is from us or not.
Once you have received the sample, you have to know how to test it, right?
There are 2 simple testing methods to verify its quality: 1HNMR for structure confirmation/residual solvents, and HPLC for product purity.
Through 1hnmr we can make sure the structure is correct, whether there are extra amounts of residual solvents, and HPLC will show you its purity and impurities contents.
#1. The solvent used for 1HNMR Testing
To run NMR tests, you have to know how to dissolve the target molecule first, and you need to find the right solvent.
As we have mentioned its solubility in our product page, it is insoluble in water or ethanol but soluble in DMSO, so DMSO will be the perfect solvent to dissolve it to run 1hnrm testing.
Here is a tip for 1HNMR testing, if you are not sure about the solubility of the molecule to be tested, try DMSO to dissolve it, DMSO is the best solvent.
Our 1HNMR spectrum of Tofacitinib tested by solvent DMSO is down below in our download section, please check.
#2. MOA for HPLC testing
To run HPLC testing on purity, we must choose the right column and mobile phase, not much importance on the brands for HPLC equipment.
Column: C18; size: 4.6*50mm; mobile phase: B(acetonitrile), A(0.02% NH4Ac); Gradient elution(B%).
Of course, this is just our method for moa and there are other different methods out there for your to explore. We found one patent for the HPLC method too, please check below.
Though it is in Chinese, if you have done HPLC before, you can see that the patent is using a longer column, with different Mobile Phases A and B by the unit.
From the table, you can also see the gradient elution method, the ratio of A/B by the minute(Their whole running time is 55 min).
Below is our testing spectrum of HPLC for your ref.
If you need a more detailed MOA on both methods, send an email to firstname.lastname@example.org directly.