Read-across/SAR posts Collection

[Yosukemino]

7. Calculating Nitrosamine Limits (MasterClass) June 2022
   @Naiffer_Host shared the recording of @conudel 's presentation, “Setting Limits for Complex Nitrosamines”. You can understand how to decide the limit of NDSRIs.

Calculating Nitrosamine Limits (MasterClass)

At the recent USP’s China Nitrosamine Workshop, Dr. Raphael Nudelman @conudel lead a true master class on ‘Setting Limits for Complex Nitrosamines’ If you want to understand how to approach limit setting, I encourage you to invest the time to watch the presentation. It will be a very well-invested time! @jxl [image] Click here to watch! Please feel free to add your questions below via reply…

8. Nitroso Flecainide July 2022
9. N-nitrosoamides - a horse of a different color July 2022
   We discussed the difference between nitrosamines and nitrosamides/carbamates/urea/guanidine. These look confusing, but they should be distinguished.

Nitroso Flecainide

Anyone having idea about AI limit of Nitroso Flecainide? What could be the AI limit as per QSAR and read across approch?

N-nitrosoamides - a horse of a different color

Of late, I am seeing an alarming trend where people are mislabeling impurities as nitrosamines, when they are really nitrosamides/carbamates/urea/guanidine. Let us understand thatthe N-nitroso compounds can be divided into two categories, the M-nitrosamines and N-nitrosamides** (Figure 1). N -nitrosamines are formally derived by the reaction of secondary and tertiary amines with nitrous acid or other nitrosating agents. These can be formally considered as “amides” of nitrous acid and are stable.…

10. Officially used surrogates for read-across method July 2022
    I visualized surrogate compounds used for read-across by EMA. I think we need more examples.

Officially used surrogates for read-across method

I want to visualize surrogate compounds used for read-across by EMA. [image] NDEA NDEA applies to five compounds. NDEA is well-known and has sufficiently robust toxicological data. [image] NDMA NDMA applies only to NMBA, despite its robust toxicological data. [image] NTHP There are compounds for NDSRI from here. NTHP is used for two, NNV and N-nitroso sitagliptin. The double bond of NTHP is the key feature. [image] N-Nitrosopiperidine N-Nitrosopiperidine applies to NMPH. T…

11. AI Limit for Nitroso Nebivolol August 2022
    @David shared deep insight for selecting a suitable read-across analog. I think the current read-across surrogates in 10 focus mainly on local similarity. I hope it will be improved in the future.

AI Limit for Nitroso Nebivolol

No limit has yet been published, as you observe; this may well be due to the difficulty of selecting a suitable read-across analogue, and I would be hesitant to do so myself without a lot more information. It may be that without further analysis (ongoing) of the complex nitrosamine data to allow us to understand how to make the extrapolations from small molecules, selection of a suitable analogue for this compound would be an impossible task. I do not believe that the compound will be potent en…

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