If you have two sets of precision test data, one from analyst 1-day1, and another one from analyst 2-day2, how exactly do you calculate the overall % RSD for both tests?
Analyst1 Analyst 2
Results 1 Results 2
mean 1 mean 2
sd 1 sd 2
%RSD 1 % RSD 2
What is the correct way to calculate overall % RSD?
Almin
Dear almin,
As per USP and ICH guidelines Precision will perform
- Repeatability: (1st set) calculate the Mean, SD and % RSD for the same (six replicates)
- Intermediate precision: (2nd set) calculate the Mean, SD and % RSD for the same ( six replicates) and also Overall Mean , SD and % RSD for the two sets (twelve replicates).
For intermediate precision case we have to check % RSD of six replicates and Overall % RSD of Twelve replicates of Repeatability and Int. precision separely.
For Japan market: Int. Precision study is different for the USP. i.e. six sets required. for details see attachment.
Regards,
Srinivas.
guidance_004_analytical_test_method_validation_-_precision_and_accuracy_sample.pdf (117.6 KB)