I want to share a paper(https://jpharmsci.org/article/S0022-3549(23)00107-7/fulltext) that refers to the case of API degradation cause to NDMA generation. Afatinib is a tertiary amine and has DMA moiety. How afatinib degrades and how NDMA generates is pretty interesting!! The author reported the DMA and nitrite amounts in FPs under stability tests. Hydrolytic degradation of drug substance was likely to play a key role in NDMA formation.
NDMA formation Due to Active Ingredient Degradation and Nitrite Traces in Drug Product