Collaborative study for the establishment of the second international standard for vancomycin.

An international collaborative study has been organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) to establish the World Health Organization (WHO) 2nd International Standard (IS) for Vancomycin. Twelve laboratories from 10 different countries participated. The potency of the candidate material, a freeze-dried preparation, was estimated by microbiological assays with sensitive micro-organisms. As the stocks of the 1st IS for Vancomycin had been completely depleted, in order to ensure continuity between consecutive batches of the WHO IS, the European Pharmacopoeia Chemical Reference Standard (CRS) for Vancomycin batch 2 was used as a standard. It had been calibrated in a large international collaborative study against the WHO 1st IS for Vancomycin. Based on the results of the study, the 2nd IS for Vancomycin was adopted at the meeting of the WHO Expert Committee on Biological Standardisation (ECBS) in 2010 with an assigned antimicrobiological activity of 109,700 IU per vial. The 2nd IS for Vancomycin is available from the EDQM.