1 Clearly define the assay's intended use relative to the desired product attribute (e.g., identity, purity, impurities, potency, concentration, stability) and acceptance specification requirements.
2 Understand how the method technology functions to generate data on the parameter of interest. Develop appropriate system suitability measures to assess method performance independently of the test sample performance.
3 Recognize and control potential sources of method and operational variability that can impact the reproducibility of assay procedure. Incorporate system suitability measures to assure the validity of each test run, and to track/trend method performance over time.
4 Confirm that the method will be scientifically sound for its intended use(s) by demonstrating its inherent performance capabilities such as accuracy, precision (intra and inter assay), linearity/range/limit of detection (LOD)/limit of quantitation (LOQ), and specificity (including for product degradants, if stability-indicating).
5 Verify that assay is robust enough under the conditions of expected use to statistically support the specification requirements for the product at each phase of development and commercialization.
6 Assure that all documentation and data from each method's lifecycle events are maintained in archived files which are complete, traceable and retrievable for use in supporting product and method knowledge management over time.
Table 1: Elements for successful analytical method development and implementation.