FDA Guideline's Update on Nitrosamines

Normativa - 4 Ottobre 2023

New guidance has recently been released regarding tolerable levels of nitrosamine-related impurities (NDSRIs) in pharmaceutical products. These new guidelines provide a recommended framework for predicting the mutagenic and carcinogenic potential of NDSRIs that may be present in drugs. Acceptable intake limits for such nitrosamines have also been established to ensure an appropriate level of safety.

The EMA has published a new update of the list of nitrosamines, with the inclusion of 5 more specific API nitrosamines than those already listed by the FDA, calculated according to the expected categorisation of their carcinogenic hazard (CPCA). 

Below is the list of the 5 new nitrosamines.


Researched on API



N-nitroso derivative of rotigotine impurity B: N-(5-hydroxy-1,2,3,4- tetrahydronaphthalen-2-yl)-N-propylnitrous amide


N-nitroso derivative of rotigotine impurity C: N-(5-hydroxy-1,2,3,4- tetrahydronaphthalen-2-yl)-N-(-2-(thiophen-2-yl)ethyl)lnitrous amide




N-nitroso-varenicline, NNV (2755871-02-2)



FDA Guidelines

The new guideline provided by the Food and Drug Administration, titled "Recommended Acceptable Intake Limits for Nitrosamine Drug Substance-Related Impurities (NDSRIs)", provide a framework for risk-based safety assessment of NDSRIs that may be present in approved and marketed drug products, as well as in products under review by the FDA.

The FDA document is fully aligned with the European Medicines Agency (EMA) guideline regarding the carcinogenic potency categorization approach for establishing the AI of nitrosamines and regarding the introduction of the Enhanced Ames Test for mutagenic risk assessment. The FDA has also published limits for about 250 potential nitrosamine-specific APIs calculated in accordance with the expected carcinogenic potency categorization.

Compared with the EMA guideline, where the limit for high carcinogenic nitrosamines is 18 ng/day, in the FDA guideline this limit is set equal to 26.5 ng/day.

EMA Guidelines

In update 16 of document EMA/409815/2020 the Committee for Medicinal Products for Human Use (CHMP) introduced important new changes to Chapter 10, "What Limits Apply to Nitrosamines on Medicinal Products?"
In particular, the carcinogenic potency categorization approach (CPCA) has been introduced to determine the AI of nitrosamines.

Another important new development is the introduction of the Enhanced Ames Test in order to allow the control of N-nitrosamine at 1.5 µg/day. The Enhanced Ames Test is a variant of the traditional bacterial mutagenesis test drafted by FDA. In this variant, the test is conducted with 5 bacterial strains of Salmonella thyphimurium and Escherichia coli pre-incubated for 30 minutes with the test item under investigation in the presence and absence of metabolic activator.

The AI of about 60 new NDSRIs and "generic nitrosamines" have also been published. Some AI published in previous revisions of the document, have also been updated and increased.

LabAnalysis provides years of experience and state of the art instrumentation to give support to the Client in monitoring the status of compliance with respect to the various changes introduced by these new Regulations.

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