u/Additional_Hyena_348

Hello everyone,

I am working on calculating the Permitted Daily Exposure (PDE) for cleaning validation and have two specific questions regarding the variables in the standard equation when a NOAEL is not available, and a LOAEL must be used instead.

1. Body Weight: Should the standard body weight used in the numerator always be 50 kg, or does this depend on the specific target patient population?
2. F5 (Modifying Factor): When extrapolating from a LOAEL to a NOAEL, I have seen F5 set to 2.5 in some cases. Is 2.5 a standard default, or should this factor change based on the severity of the toxicity observed at the LOAEL?

Any insights, guideline references (like EMA or ICH), or practical advice on how you handle these variables would be greatly appreciated.

Thank you!