Anhydrous Citric Acid

Type of Posting: 
Notice of Adoption of Harmonized Standard
Official Date: 
Expert Committee: 

A harmonized standard for Anhydrous Citric Acid has been approved by the Pharmacopeial Discussion Group (PDG) as described in its PDG Sign-Off Cover Page. Having reached Stage 6 of the PDG process, the Anhydrous Citric Acid monograph has been formally approved by the USP Monographs—Excipients Expert Committee in accordance with the Rules and Procedures of the 2010–2015 Council of Experts.

Changes from the existing USP–NF monograph include:

  • Corrected sample preparation in Limit of Oxalic Acid to be consistent with data from sign off text.
  • Corrected Standard preparations in Clarity of Solution consistent with sign off text and adjusted acceptance criteria to allow for clarity to be compared to Standard suspension A as well as water.
  • Clarified acceptance criteria for Color of Solution to be consistent with verbiage in the sign off text.
  • Added sample size of 2.0 g for Water Determination consistent with sign off.
  • Labeled the following tests as USP National text: Heavy Metals, Bacterial Endotoxins, Sterility, Packaging and Storage, Labeling, USP Reference Standards.

The Anhydrous Citric Acid monograph will be incorporated into and become official with Supplement 1 to USP 35–NF 30.

Should you have any questions about the Anhydrous Citric Acid monograph, please contact Kevin Moore (301-816-8369 or For any questions about the PDG and its processes, please see the Pharmacopeial Harmonization Web page or contact Mario Sindaco (301-816-8246 or

* PDF monograph updated to include a change from the Expert Committee that clarifies the Color of Solution procedure and acceptance criteria for the user. This clarification was missing in the initial posting of the PDF monograph.