Citric Acid Monohydrate

Type of Posting: Notice of Adoption of Harmonized Standard

Posting Date: 30–Sep–2011; updated 14–Oct–2011* (updated 27–Feb–2017**)

Official Date: 01–Aug–2012

Expert Committee: Monographs—Excipients

**Coordinating Pharmacopeia: EP

A harmonized standard for Citric Acid Monohydrate 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 Citric Acid Monohydrate 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 for Clarity of Solution to be 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 0.5 g in Water Determination to be 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 Citric Acid Monohydrate monograph will be incorporated into and become official with Supplement 1 to USP 35–NF 30.

**Should you have any questions about the Citric Acid Monohydrate monograph, please contact Dr. Tong (Jenny) Liu (240-221-2072 or For any questions about the PDG and its processes, please see the Pharmacopeial Harmonization Group or contact Richard Lew at (240-221-2060 or

**The previous PDG sign-off Cover Pages and Stage 6 postings are included as below:

*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.