New Ph. Eur. Chapter Comparability of Alternative Analytical Procedures

Following the draft chapter published in 2022, the new European Pharmacopoeia (Ph. Eur.) general chapter Comparability of alternative analytical procedures (5.27) has now been published in Supplement 11.5. While this text does not introduce any new requirements, it provides useful information on how users wishing to employ an alternative analytical procedure can demonstrate its comparability to the pharmacopoeial procedure. The chapter shows the comparability process and lists the prerequisites for the comparability study.

Demonstration that the alternative procedure meets its performance criteria during validation is not sufficient to imply comparability with the pharmacopoeial procedure. The performance of both procedures must be assessed and compared. Therefore, it is required that the pharmacopoeial procedure is implemented as defined in general chapter 5.26. Implementation of pharmacopoeial procedures, including verification experiments if appropriate (see also the Examples of Analytical Method Implementation).

Comparability Study

The purpose of the comparability study is to evaluate whether the results and performance of an alternative analytical procedure are comparable to those of the pharmacopoeial procedure. The evaluation typically involves a comparability testing study that generates comparative data followed by statistical evaluation of the test results. When the equivalence as part of the comparability study is accepted, the alternative procedure may be considered statistically equivalent to the pharmacopoeial procedure. The equivalence testing approach may also be used for biological assays. However, comparability of alternative microbiological methods is covered in general chapter 5.1.6. Alternative methods for control of microbiological quality.

If data from two analytical procedures cannot be statistically compared, the conclusion on comparability is based on evidence that the results of the alternative procedure lead to the same unequivocal decision that would be made with the pharmacopoeial procedure, which is also the ultimate goal of the comparability study.

More information is available in the European Pharmacopoeia.