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Photostabilty (ICH Q1B)

We monitor the exposure to near UV fluorescent lamp by the quinine chemical actinometry method according to ICH Q1B, Option 1 (Annex 4), which means that the length of exposure should be sufficient to ensure a change in absorbance of at least 0.9.

Can the same criteria be applied for monitoring the exposure to the cool white fluorescent lamp?

According to guideline (ICH Q1B, Annex 4): “For other light sources/actinometric systems, the same approach may be used, but each actinometric system should be calibrated for the light source used”.

Therefore, can the same change in absorbance be applied?