Hi,
I recommend checking out the following link for better understanding of the calculation:
Moreover, if there’s any known Nitrosamine impurity, it should be calculated as AI ng per day / MDD mg per day.
Eexample: NDMA= 96/500= 0.192 or 0.2 ppm. This limit also applies to DS and DP.
You may raise your question to DS team how they calculate NDMA limit is 880 ppm ?
Regards,
Dr. Dinkar