Skip to main content

Compendial Notice: USP Proposes Revisions to General Chapter <81> Antibiotics—Microbial Assays

Type of Posting: General Announcement

Posting Date: 27–Aug–2010

USP is proposing revisions to General Chapter <81> Antibiotics—Microbial Assays that will appear in Pharmacopeial Forum 36(5) [Sept–Oct 2010]. The proposed revisions update the general chapter in its entirety so that it reflects current industry practices. The revisions are as follows:

  • The general chapter has been redesigned and the contents are reorganized for clarity.
  • The tables have been updated to delete references to 1) antibiotics for which the monograph specifies an HPLC procedure and 2) those for which there is no official USP monograph.
  • The contents of all tables have been sorted by antibiotic name for ease of use.
  • The Calculations section has been expanded to provide details about the interpretation of data. In an effort to make the general chapter a more inclusive public standard, references to Design and Analysis of Biological Assays <111> have been eliminated.
  • Sample calculations have been included in the chapter to provide guidance. In the future, USP intends to provide an online compendial tool that may be used to evaluate the data generated from microbial assay procedures.
  • Because Federal Master Standards are no longer available, references to them have been updated.
  • A statement has been added to indicate that the procedures should be performed under aseptic conditions.
  • Additional information has been provided about the maintenance of microorganisms for the assays.

Interested parties are invited to comment on the proposal. The comment deadline is December 15, 2010.

Note—Because of the large number of crossed-off pages, the pages in the print version of PF 36(5) represent only the added proposed revision of General Chapter <81> Antibiotics—Microbial Assays. The complete text of this proposal is available at the link below and in the online electronic version of PF 36(5).

For further information, contact Ahalya Wise, M.S., (