Dobbelaer R, Daas A, Milne C
Scientific Institute of Public Health, Juliette Wytsmanstraat 14, B-1050 Bruxelles, Belgium.
Pharmeuropa Bio. 2004 Jan;2003(2):77-90.
A collaborative study was initiated by the European Directorate for the Quality of Medicines (EDQM), to assign a potency value for candidate batch 2 of European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for Hepatitis B (rDNA) antigen in vitro assays, for both method A and method B by calibrating them against the Ph. Eur. BRPs, batch 1 for methods A and B respectively. The study was prompted by the observation that the first batch of BRP for method B appeared to have lost potency over time. BRP 1 for method A showed no loss in potency, however stocks of the material were nearing depletion. Eleven laboratories participated in the study and all reported results. Participants performed 3 independent assays using both method A and method B. Method A was used to assess BRPs for method A and method B was used to assess BRPs for method B. Since BRP 1B was suspected to have lost potency, an additional sample was included in the method B test in an attempt to clarify the situation. BRP 1B was also assayed in method A against BRP 1A in the hope of also attaining further information by comparing the results from this study to those obtained in the original study to establish the first batch of BRP [1]. Although it was not the primary aim of this study to correlate in vitro potency with the immunogenicity assay in mice, a number of interested parties also performed the mouse in vivo assay to obtain data on the behaviour of the candidate BRPs in this assay. For method A, potency estimates were satisfactory in terms of repeatability and reproducibility. The candidate material was therefore assigned a value of 16.6 micrograms/ml. For method B, it appeared that the observation of reduced in vitro potency of BRP1 was confirmed. Despite the attempt to clarify the situation with additional studies, it was not possible to assign a potency value with the results obtained. A small-scale collaborative study will be organised to determine an appropriate value for the candidate BRP for method B. The results from the in vivo study while highly variable showed no evidence of a shift in the in vivo potency for either BRP 1A or BRP 1B. It should be noted that the in vitro method for determination of hepatitis B vaccine potency is under revision due to the discontinuation of the Auszyme kit from Abbott, which is required to perform the current assays. Once an alternative assay has been established, the suitability of the reference preparations or establishment of new reference preparations will be required. The candidate material for method A BRP was adopted by the European Pharmacopoeia Commission at its session in November 2003, as the European Pharmacopoeia Hepatitis B vaccine (rDNA) method A, batch 2.
欧洲药品质量管理局（EDQM）发起了一项合作研究，旨在通过将欧洲药典（Ph. Eur.）生物参考制剂（BRP）的方法A和方法B分别与Ph. Eur. BRP批次1进行校准，为欧洲药典乙型肝炎（rDNA）抗原体外测定的候选批次2赋予效价。该研究的起因是观察到方法B的第一批BRP随着时间推移似乎效价降低。方法A的BRP 1效价未降低，但该材料库存接近耗尽。11个实验室参与了该研究并报告了所有结果。参与者使用方法A和方法B进行了3次独立测定。方法A用于评估方法A的BRP，方法B用于评估方法B的BRP。由于怀疑BRP 1B效价降低，在方法B测试中纳入了一个额外样本，试图澄清情况。BRP 1B也在方法A中针对BRP 1A进行了测定，希望通过将本研究结果与原始研究结果进行比较，也能获得更多信息，以确定第一批BRP[1]。尽管本研究的主要目的不是将体外效价与小鼠免疫原性测定相关联，但一些相关方也进行了小鼠体内测定，以获取候选BRP在该测定中的行为数据。对于方法A，效价估计在重复性和再现性方面令人满意。因此，候选材料被赋予16.6微克/毫升的值。对于方法B，BRP1体外效价降低的观察结果似乎得到了证实。尽管试图通过额外研究澄清情况，但根据获得的结果无法赋予效价值。将组织一项小规模合作研究，以确定方法B的候选BRP的合适值。体内研究结果虽然差异很大，但没有证据表明BRP 1A或BRP 1B的体内效价发生变化。应当指出，由于执行当前测定所需的雅培Auszyme试剂盒停产，乙型肝炎疫苗效价的体外测定方法正在修订。一旦建立替代测定方法，将需要参考制剂的适用性或建立新的参考制剂。方法A BRP的候选材料在2003年11月的会议上被欧洲药典委员会采用，作为欧洲药典乙型肝炎疫苗（rDNA）方法A，批次2。
