% Area tolerance a peak in blank

[MaiLy]

Some time we have seen a small peak in blank with the same retention at the interest peak. Although area of this peak is small, but I wonder that how much % area of this peak compare to the interest peak that we can say it would not impact, and it pass the system suit. How can we calculate it? Any advice, would greatly appreciate.

Best regards,
Maily

[HPLC chemist]

Per ICH Q3 a related substance can be no more than 0.05% wt/wt of the API i the drug product. Assuming this peak is a treated like a related substance the tolerable peak area is a maximum of 0.05% of the peak area for the API assay peak.

[HPLC chemist]

You can try to move this peak by adjusting the mobile phase composition so R>1.5

[MaiLy]

Per ICH Q3 a related substance can be no more than 0.05% wt/wt of the API i the drug product. Assuming this peak is a treated like a related substance the tolerable peak area is a maximum of 0.05% of the peak area for the API assay peak.

Thank you so much. I have thought the same.

Maily