Validating test methods
The nature of the test material itself changes how a test is run and the validation protocol.
Consequently, testing for objectionable organisms is different when testing a diuretic for hypertension or an antibiotic for treating pneumonia.
Validity refers to the degree in which our test or other measuring device is truly measuring what we intended it to measure.
The test question “1 1 = _____” is certainly a valid basic addition question because it is truly measuring a student’s ability to perform basic addition.
Also, a procedure that works perfectly well for checking the bioburden of granulated sugars may fail with sodium chloride.
These differences make full coverage of the topic impossible within the context of this primer.
Yet, it is necessary to validate microbiological tests if they are to be useful for controlling the quality of drug products and devices.This article will present the general considerations that apply to most microbiological tests.However, three excellent publications are available to analysts preparing validation study protocols for microbiological methods (see Suggested Reading).Some tests, such as bioburden or viral titer tests, are quantitative in nature while other tests, such as those for the presence of objectionable organisms, are qualitative.As with chemical tests, these differences necessitate different validation approaches.
This is an important step since a finding of "no growth detected" is meaningless if the medium was incapable of growing any organisms.