1/2 March 2023
After the last revision of the Q&A document on nitrosamine contamination in February this year, three further updates (Rev. 8 of 24 March, Rev. 9 of 20 May and Rev. 10 of 23 June 2022) have been made in the period of 12 weeks.
The following is a summary of the respective additions in the answer texts to the individual questions:
4. What are the currently identified risk factors for presence of nitrosamines? (Rev. 8)
The risk factors for the formation of nitrosamine impurities were divided into three categories and partly completed by more detailed explanations:
5. What to do if after submission of Step 1 and/or step 2 responses, new information (e.g. related to new potential risk factors or root causes) is identified? (Rev. 10)
In the new wording of the answer, the expectations on the marketing authorisation holders are specified as follows:
Particular attention should be paid to potential nitrosamine sources from APIs. A high risk is the simultaneous presence of amines and nitrite traces during formulation of the final product or its storage.
8. How should confirmatory tests be conducted by MAHs and manufacturers? (Rev. 8)
The answer to this question specifies the case where the cause of nitrosamine contamination is only at the stage of manufacture of the API. If this is proven beyond reasonable doubt, confirmatory testing may be limited to the API or intermediates only and need not be extended to the finished product.
The prerequisites for this are:
The responsibility for the confirmatory testing strategy lies with the marketing authorisation holder. The testing strategy must be justified by the risk assessment of the finished product and documented in the marketing authorisation holder's pharmaceutical quality system.
10. Which limits apply for nitrosamines in medicinal products? (Rev. 9, Rev. 10)
In the table of nitrosamines, seven additional nitrosamines with the corresponding limits have been added. It is explicitly stated that the authorities do not accept a negative Ames test as sole evidence for the absence of mutagenic properties of a nitrosamine. The fact that some nitrosamines exhibit in vivo mutagenicity despite negative Ames test results puts the significance of this test into perspective and additional testing is required to classify a nitrosamine compound as a Class 5 impurity according to the ICH M7(1) guideline.
In the last update of the answer to this question, N-nitrosodabigatran and the associated limit value were added to the table. The table was extended by an additional column ("Source") in which the active substances are indicated in each case as a potential source of the corresponding nitrosamines. Furthermore, it is explained in more detail how the limit value must be determined if the active substance is present in the product as a salt, hydrate or in the solvate form.
14. What is the approach for new and ongoing marketing authorisation applications (MAA)? (Rev. 10)
Reference to the new risk assessment template to be used in marketing authorisation applications has been included in the answer text to this question. The template can be found on the CMDh website on nitrosamine impurities.
15. When should a test for nitrosamines be included in the MA dossier? (Rev. 8)
The following clarifications have been introduced in the text of the answer to this question:
20. What are the regulatory steps taken by authorities following the identification of an N-nitrosamine exceeding the AI? (Rev. 9)
This question and the corresponding clarifications have been newly included in the document. It describes the regulatory steps taken by authorities for so-called scenario A cases. A scenario A case is when one or more nitrosamines are detected in a finished medicinal product that are above the AI limit or when the sum of all detected nitrosamines exceeds the 1 in a 100,000 lifetime risk.
For scenario A, the following measures are taken:
In parallel to the update of the EMA/CMDh Q&A document, the corresponding CMDh document containing the practical guidance for holders of national marketing authorisations (including mutual recognition and decentralised marketing authorisations) was also revised.