When a pharmaceutical compound is newly discovered, it is necessary to develop an analytical method (or assay method) for the active ingredients of the compound. The assay method should be in compliance with some established specifications. CGMP [21 CFR 211.194(a)] requires that the assay method must meet certain standards of accuracy and reliability. As mentioned in Chapter 1, assays and specifications of the USP/NF constitute the legal standards recognized by the official compendia of the federal Food, Drug and Cosmetic Act. As a result, the CGMP [21 CFR 211.194(a) (2)] indicates that use of assay methods described in the USP/NF is not required to validate accuracy and reliability of analytical procedures. However, any proposed new or revised assay methods for submission to the compendia must be validated and documented with sufficient laboratory data and information according to the requirements stated in the USP/NF. The new or revised assay methods are then reviewed for their relative merits and disadvantages by the members of the USP Committee of Revision.