BRIEFING

 〈162〉 Diphtheria Antitoxin Potency Testing for Human Immune Globulins. This proposal is based on the chapter official as of May 1, 2022. It is proposed to make the following changes:

1. In the Calculation subsection:

   • Delete the repetitive definition for cutoff dilution.

   • Update "mean" to "geometric mean" to align it throughout the section.

   • Delete the number "four" as only one sample is used per plate.

2. Under System suitability, delete "Standard solution and Sample solution" as cutoff dilution values, as the Standard solution and Sample solution may or may not be within one serial dilution of each other.

  Additionally, minor editorial changes have been made to update the chapter to current USP style.

 (BIO3: K. Chandra)

 Case ID—SUB-2230