Nitrosamine testing on stability samples?

Should i test nitrosamin impurity on retained samples only ie on room temperature or it should pass on long term and short term stability too (condition 40c/75rh and 30c/65)

Did you identify the risk of forming Nitrosamine in your products? I would say where all starts before running to the lab to conduct testing…

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Thank you for the response , yes i detected nitrosamine in one of metformin product , on room temperature it is not exceeding the limit but on 40c/rh75% it fails , is it necessary to control the finished product on long term and short term samples ?? @Naiffer_Host

Please refer to the Joerg et al @schlinjo1975 publication in the post below. The stability studies performed and how it was mitigated is a model to follow in my opinion

In your case, since the NDMA results are within acceptable levels during the long term storage but fail in accelerated stability study, additional studies should be performed at intermediate condition. Extrapolation of the shelf-life can be performed using the ICH Q1E guidance.

Excerpts from the ICH Q1A are reproduced below:

Where ‘significant change’ occurs during six months storage under conditions of accelerated testing at 40_C ± 2_C/75 percent RH ± 5 percent, additional testing at an intermediate condition (such as 30_C ± 2_C/60 percent RH ± 5 percent) should be conducted for drug substances to be used in the manufacture of dosage forms tested long term at 25_C/60 percent RH and this information included in the Registration Application. The initial Registration Application should include a minimum of 6 months data from a 12 months study.

Please note that the key to controlling NDMA in Metformin is controlling dimethyamine (PhEur. Impurity-F, a process-cum-degradation impurity) to as low as reasonably possible along with using the right grade of excipients (devoid of nitrites).

I hope this helps.


@Muzaffar thank you forvthe valuable information, i would like to ask what you mean with long term samples ? For my case it is stable on toom temperature , is it a requirement to study my samples on any condition?? Or room temperature sample for two years will be accepted

@Mittalkumar any thoughts?

Dear daliasalamesh,

Can you share me by which analytical tool are you using for this testing (RT and stress conditions)?

If GCMS (single quadrupole) or Triple quadrupole or LCMSMS / LC-HRMS?

@daliasalameh I believe by “room temperature” you mean to say the long term storage conditions i.e. 25°C ± 2°C/60% RH ± 5% RH. I suggest you generate the stability data at these conditions and also at intermediate conditions and assign the shelf life based on real-time data.

@Mittalkumar it is by LCMSMS

It would be great if it is on ACC batches

Either 6M ACC or Long term real time interval samples.
If you prove on 6M ACC Samples, then as per Q1E extrapolation, then same will be considered as LT samples

in my opinion., the standard stability decision criteria to be followed ( i.e., intermediate conditions to be analyzed, and determine the interim-shelf life of the product in line with ICH Q1E), particularly because its an degradant, treated similar to that of other impurities.

also, more important is the control strategy for controlling the extent of degradation. ( ref. @muzzafar’s post :point_right: )

Hi daliasalameh,

Thanks for confirmation.

In this case I would suggest result reconfirmation with another method (orthogonal method) such as LC-HRMS which can provide high resolution mass data. Also it can easily differentiate matrix effect and provide exact mass of NDMA impurity.

Specially in Metformin lot of companies was facing issue to DMF interference due to high matrix effect and got false positive NDMA peak in their drug product.

I would suggest to reconfirm it first and for stability testing you go with 6M 40/75% and confirm it.

Mittalkumar Bhavsar.

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@Mittalkumar thanks for sharing your advice and experience. It call me attention those artifacts and false positives you are mentioning.
Can you or tag someone in the community that could share more information or any publication about these challenges.

@Aaron and @AmandaGuiraldelli just in case you have any additional references.

thank you for the response, is there any regulation force me to do the tets on accelerated conditions ? i mean published and clear regulation that asks to do the testing on LT or Acc conditions
is it enough to test my product initially ?

Analysis of retain samples is only from the risk assessment perspective ; this is to enable any immediate action to be enforced for the products on the market or the actions related to manufacturing/vendor controls etc.

further wrt stability testing, nitrosamines are another class of critical impurities, and the requirements for determining the shelf life would remain the same. we need to consider the other points suggested on controls strategy by @Muzaffar and analytical method by @Mittalkumar .

as per the specific guidance, apart from ICH Q1, FDAs guidance is applicable & relevant to review the requirements. and if you are looking for specific & particular mention of nitrosamine impurities in the guidelines, i guess, need to do little more search, if that is too much of a requirement!

@daliasalameh please look into the latest update issued by us fda
The data in the NDA/BLA and ANDA meeting package should include, at a minimum, the following:

Description of the formulation design strategy employed to reduce the formation of NDSRIs in the drug product.
**Supporting manufacturing information and, at a minimum, three months of accelerated stability data demonstrating control of NDSRI.**
For approved NDAs and ANDAs that require reformulation as part of a mitigation strategy, in vitro or in vivo bioequivalence bridging studies.

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