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Type of Posting: Notice of Intent to Revise

Posting Date: 29–Dec–2011

Targeted Official Date: Revision Bulletin, 01–Feb–2012

Expert Committee: Monographs—Small Molecules 4

In accordance with section 7.05(c) of the 2010–2015 Rules and Procedures of the Council of Experts, this is to provide notice that the USP Monographs–Small Molecules 4 Expert Committee intends to revise the Limit of Methyldopa and Carbidopa Related Compound A test in the Carbidopa monograph to reflect the change in the way of quantification of Carbidopa Related compound A. Recent evaluation of the current lot of USP Carbidopa Related Compound A RS by USP scientific staff has determined that it no longer suitable for its compendial usage as described in USP34–NF29. The following changes are proposed:

  • Use USP Carbidiopa RS to quantify Carbidopa Related compound A.
  • Remove the USP Carbidopa Related Compound A RS from USP Reference Standards section.

It is anticipated that the proposed revision will be published as a Revision Bulletin on January 27, 2012 with an official date of 01 February 2012, pursuant to section 7.02 of the Rules and Procedures.

Should you have questions regarding the monograph, please contact Ravi Ravichandran, Ph.D., Principal Scientific Liaison to the Expert Committee (301-816-8330 or For questions regarding the reference standards, please contact Reference Standard Technical Services at