
For stability studies, ICH specifies tolerances of +/2 deg. C and +/5% RH. What are the required accuracies (i.e. allowable calibration error) of the instruments (BAS) monitoring these conditions? How about a permeability chamber (as per USP) requires tolerances of +/2 deg. C and +/3% RH?

How to define worstcase scenario for temperature and humidity monitoring (based on mapping data)? What are the criteria to relocate monitoring sensor if worst case location(s) changed during subsequent mapping studies?
[quote=sthillai]1. For stability studies, ICH specifies tolerances of +/2 deg. C and +/5% RH. What are the required accuracies (i.e. allowable calibration error) of the instruments (BAS) monitoring these conditions? How about a permeability chamber (as per USP) requires tolerances of +/2 deg. C and +/3% RH?
 How to define worstcase scenario for temperature and humidity monitoring (based on mapping data)? What are the criteria to relocate monitoring sensor if worst case location(s) changed during subsequent mapping studies?[/quote]
I think maximum accuracy of 0.3 deg C can be acceptable. Monitoring location can be change by proposing appropriate change request
I want to raise this question again.
I know  WHO recommends the use of sensors with an accuracy of at least +/ 0.5. But i don’t understand why. I think the measurement accuracy should be no worse than it was when studying stability ±2. If for the usual storage mode the study of stability at a temperature of 25 ± 2, then there is no contradiction to use devices with accuracy of 0.5, because 25 is the upper limit of the range… It’s just not clear why exactly 0.5, and let’s say not 1? The study of the storage mode in the refrigerator takes place at 5 ± 3. 5 is the average, how far will it be correct to consider the permissible limits from 2 to 8, taking into account the fact that the measurement error is ± 0.5?