The purpose of validation of an analytical method is to ensure that the adopted method meets the requirements for the intended analytical applications. The analytical method must be validated in case of establishing drug quality standards, changing pharmaceutical synthetic processes or the components of preparation, or revising the original analytical method. For biological product quality control, physicochemical analytical method and biological determination method can be employed. Because the principle of physicochemical analytical method is applicable for both chemical and biological products, this Guidelines is suitable for corresponding method validation on biological products with special attention paid to their unique characteristics in the validation study. Compared to physicochemical analytical methods, more factors are present in biological determination methods that are out of scope of this Guidelines.

The analytical items that need validation include identification test, impurity determination (limit or quantitative analysis), content determination (including characteristic parameters [e.g., drug dissolution rate, release rate, etc.] and content/potency determination).

The validation indexes include specificity, accuracy, precision (including repeatability, intermediate-precision, and reproducibility), detection limit, quantitation limit, linearity, range and robustness. Standard substance must be utilized in the validation of analytical method. Because of the intrinsic characteristics of validation methods and possible influences from analytes, the parameters to be validated should be decided depending on specific conditions.