USP PF49(3) 的一篇启动文章“Selecting an Appropriate Volume for the Subvisible Particles Per Container Calculation”曾经讨论过类似的问题——不溶性微粒的结果如何从 counts/ml换算成counts/container.  结论性段落如下，供参考：

There is no single “correct” approach for selecting a volume multiplier. It may also be acceptable and justifiable to use different volume multipliers across different programs, but a volume multiplier selection should be selected for a given program for tracking historical results and ensuring product quality and stability assessment. As a hypothetical example, a liquid DP during the clinical and commercial stage may use the labeled volume (minimum deliverable volume/nominal volume); for a lyophilized DP at the early clinical stage, the reconstitution volume may be used, while later at the pivotal or commercial stage the minimum deliverable volume (equivalent to labeled dose) may be used. For a legacy commercial product presented as a lyophilized DP in a vial, the reconstitution volume may be used as the volume multiplier for maintaining historical tracking consistency. The resulting particles-per-container value is often similar among each of these multiplier selections. Nevertheless, maintaining a consistent multiplier selection is important for monitoring product consistency and stability. For products with variable dosage (such as weight based) or dosage that could be less than the contents of a single vial or a combination of multiple vials, the practice of using the labeled volume to determine the particles per container is still recommended as it is representative of the volume that could be used from that container.

使用标示量复溶体积or实际复溶体积是基于你自己的产品风险和实际情况来决定的。若你的冻干制剂标示量为5 mL，实际复溶体积测量为5.02±0.05 mL应选择标示量计算EU/剂。

实际复溶体积又如何测量：

重量法：

容量法:

建议使用EU/剂；建议使用实际复溶体积。