Collaborative study for the establishment of the 3rd international standard for neomycin.

: An international collaborative study was organised to establish the World Health Organization (WHO) 3(rd) International Standard (IS) for neomycin. Ten laboratories from different countries participated in the collaborative study. The potency of the candidate material, a freeze-dried preparation, was estimated by microbiological assays with sensitive micro-organisms. To ensure continuity between consecutive batches, the 2(nd) IS for neomycin was used as a standard. Based on the results of the study, the 3(rd) IS for neomycin was adopted at the meeting of the WHO Expert Committee on Biological Standardization (ECBS) in 2012 with an assigned potency of 19,050 IU per vial. The 3(rd) IS for neomycin is available from the European Directorate for the Quality of Medicines & HealthCare (EDQM).