This question is addressed in the Ph. Eur. General Notices. The tests and assays described are the official methods analytical procedures upon which the standards of the Pharmacopoeia Ph. Eur. are based. With the agreement of the competent authority, alternative methods of analysis analytical procedures may be used for control purposes, provided that the methods used they enable an unequivocal decision to be made as to whether compliance with the standards of the monographs would be achieved if the official methods procedures were used (cross-validation). In the event of doubt or dispute, the methods of analysis analytical procedures of the Pharmacopoeia Ph. Eur. are alone authoritative. It is not the role of the EDQM to approve alternative methods procedures or reagents.