Dears,
Kindly we need to find a solution for ;
In case of Impurities categorized ; Category 5 according to their structural alerts using CPCA tool flow chart we need to know are these impurities are required to be analyzed or not? and in case of Yes; Recommend the intervals of testing 
Regards,
@Heba94yahia I am assuming that your question, ‘Are these impurities required to be analyzed?’ is the conclusion of your risk assessment.
In an ideal pathway, your team conducted a risk assessment and identified a high risk of forming such a structure. Confirmatory testing of the impurity (or impurities) will follow. A toxicological assessment of the structure(s) might or might not be needed to justify a higher limit than suggested by CPCA.
Also, pay special attention to your regulatory advice; the expectations might differ from agency to agency.
I’ll add that it feels like a couple of steps may be in the process of being skipped.
If, on paper, you have alert structures, you should confirm that nitrosiation is possible via the NAP test. If nitrosiation is shown to be possible, then method development, validation, and confirmatory testing of the impurity(s) is needed. Then, and only then, can a control strategy, with testing intervals, be determined.