SOP on Validation of Analytical Test Procedures
1.0 Purpose: This SOP defines the characteristics to be evaluated for the validation of analytical test methods.
2.0 Scope: This SOP applies to Quality Assurance staff.
3.0 Responsibility: Quality Assurance Manager to ensure that the procedure is followed.
4.0 Materials and Equipment: As required
5.0 Procedure: The principal purpose of analytical validation is to ensure that a selected analytical procedure will give reproducible and reliable results that are adequate for the intended purpose. The characteristics that may need to be specified for analytical procedures are –
Accuracy: The accuracy of an analytical method is the closeness of test results obtained by that method to the true value. The accuracy may be determined by application of the analytical method to an analyte of known purity (e.g. reference standard) or by comparison of the results of the method with those of a second, well-characterized method, the accuracy of which has been stated or defined.
Precision is a measure of either the degree of reproducibility or of repeatability of the analytical method under normal operating conditions. Assays in this context are independent analysis of samples that have been carried through the complete analytical procedure from sample preparation to final test result. The repeatability is assessed using a minimum of six determinations at 100% of the test concentration.
Specificity: The specificity of a procedure is its ability to measure the analyte in a manner that is free from interference from other components in the sample being examined (e.g impurities, degradation products, ingredients other than analyte).
Detection limit: It is the lowest amount of analyte in a sample that can be detected but not necessarily quantitated, under the stated experimental conditions. The detection limit is generally determined by the analysis of samples with known concentrations of analyte and by establishing the minimum level at which the analyte can be reliably detected.
Quantitation limit: It is the lowest amount of analyte in a sample that can be determined with acceptable precision and accuracy under the stated experimental conditions. The Quantitation limit is generally determined by the analysis of samples with known concentrations of analyte and by establishing the minimum level at which the analyte can be determined with acceptable accuracy and precision.
Linearity and range: The linearity of an analytical method is its ability to elicit test results that are directly proportional to the concentration of analyte in samples within a given range. The range of an analytical method is the interval between the upper and lower levels of analyte, that have been demonstrated to be determined with a suitable level of precision, accuracy, and linearity using the method.
Ruggedness: The ruggedness of an analytical method is the degree of reproducibility of test results obtained by the analysis of the same samples under a variety of conditions. The ruggedness of an analytical method is determined by analysis of aliquots from homogenous lots in different laboratories, by different analysts, using operational and environmental conditions that may differ but are still within the specified parameters of the assay. The degree of reproducibility of test results is then determined as a function of the assay variables.
Robustness: The robustness of an analytical method is a measure of the capacity to remain unaffected by small but deliberate variations in method parameters and provides an indication of its reliability during normal usage.