Merck has discovered that nitrosamine NTTP in its blockbuster diabetes medications arose mostly during storage, as well as during manufacturing and believes it can resolve the problem by the end of the year


Follow the discussion here:


This article quotes the assignable RC to Mfg process and storage.
It further states, The Co has incorporated stringent QC tests as a corrective action.
Hopefully there will be ample preventive actions incorporated into the Mfg and storage processes. Can be an interesting case study if shared/published.


About 40% of the drugs will need to address this issue of nitrosamines, and that is a conservative estimation. We have tough times ahead of us. Wait till they start looking into the anti-depressants, most of which, like the “lol” drugs have possibility of forming nitrosamines. I am worried how the patient population that is already compromised in some way, react if they are told that they have been given drugs which have high levels of cancer causing impurities.


Interesting Merck found NTTP (also called Nitroso-STG-19) in three drugs with sitagliptin: Januvia, Janumet, and Steglujan but Nitrosamine levels in a related extended-release therapy, Janumet XR, were too low to be measured, the company said.

Dear Naiffer,
Is there a published source for this information:

  • The nitroso-impurity appears in both as a process impurity in the API and in the drug product, which seems to increase over time during storage

What is the actual root cause for increasing NTTP?
i) Due to presence of Nitrite in excipients?
ii) Due to storage conditions?
iii) Due to packaging material?
iv) Due to API?

From this I have understood as, still Merck is working on control strategy to controlled the NTTP impurity?