Collaborative Study for the Calibration of the Ph.Eur. Prekallikrein Activator in Albumin Biological Reference Preparation batches 8, 9 and 10.

An international collaborative study was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe) to calibrate replacement batches for the current European Pharmacopoeia (Ph. Eur.) Prekallikrein Activator (PKA) in albumin Biological Reference Preparation (BRP) whose stocks were dwindling. The study was run in the framework of the Biological Standardisation Programme (BSP) of the Council of Europe and the European Union (EU) Commission. Twenty-four laboratories from official medicines control authorities and manufacturers in Europe and outside Europe took part in the study. Three candidate replacement batches were produced with albumin solutions artificially spiked with a PKA concentrate to increase their PKA level. Participants were requested to evaluate the candidate batches against the 3rd World Health Organization (WHO) International Standard (IS) for Prekallikrein activator in albumin (16/364) using their routine assay method. The Ph. Eur. PKA in albumin BRP batch 7 (BRP7) was also included in the test panel to ensure the continuity of the consecutive BRP batches. The 3 candidate replacement batches were considered suitable for their intended use as BRPs. The study confirmed the stability of the PKA content of the current BRP7. Thermal stress study on the candidate batches confirmed the stability of their PKA activity. In December 2023, the Ph. Eur. Commission officially adopted the 3 candidate batches as Ph. Eur. PKA in albumin BRP batches 8, 9 and 10 with assigned potencies of 37 IU/vial, 33 IU/vial and 34 IU/vial, respectively. The activity of the 3 new batches of Ph. Eur. PKA in albumin BRP will be regularly monitored.