HUMPHREY J H, LIGHTBOWN J W, MUSSETT M V, PERRY W L
Bull World Health Organ. 1954;10(6):901-9.
In 1950, the Department of Biological Standards, National Institute for Medical Research, London, was authorized by the WHO Expert Committee on Biological Standardization to proceed with the establishment of an International Standard for Dihydrostreptomycin. A 50-g batch of dihydrostreptomycin was obtained and was compared with the Standard Preparation of Dihydrostreptomycin of the Food and Drug Administration (FDA), United States Department of Health, Education and Welfare, in a collaborative assay in which seven laboratories in five countries participated.In all, 76 assays were carried out; 62 of these were done by biological methods, using Staphylococcus aureus, Bacillus subtilis, or Klebsiella pneumoniae, and the remaining 14 by physicochemical methods. The results were subjected to standard methods of analysis, and the overall weighted mean potency (calculated from the results of biological assays only) was 0.958, with limits of error of 99.6% to 100.4%.Since the FDA Standard Preparation is considered to be substantially pure dihydrostreptomycin sulfate, the content of dihydrostreptomycin base (after allowing for known moisture content) is assumed to be 79.2%. The potency of the International Standard has been established as 760 International Units per mg, so that, on the foregoing assumption, one International Unit may be regarded as equivalent to the activity of one microgram of dihydrostreptomycin base.
1950年，伦敦国立医学研究所生物标准部获世界卫生组织生物标准化专家委员会授权，着手制定双氢链霉素国际标准。获取了一批50克的双氢链霉素，并在一项有五个国家的七个实验室参与的协作分析中，与美国卫生、教育与福利部食品药品管理局（FDA）的双氢链霉素标准制剂进行比较。总共进行了76次分析；其中62次采用生物学方法，使用金黄色葡萄球菌、枯草芽孢杆菌或肺炎克雷伯菌，其余14次采用物理化学方法。对结果进行了标准分析方法处理，总体加权平均效价（仅根据生物学分析结果计算）为0.958，误差范围为99.6%至100.4%。由于FDA标准制剂被认为是基本纯的硫酸双氢链霉素，双氢链霉素碱的含量（考虑已知水分含量后）假定为79.2%。国际标准的效价已确定为每毫克760国际单位，因此，根据上述假设，一个国际单位可被视为等同于一微克双氢链霉素碱的活性。
