Anhydrous Dibasic Calcium Phosphate

Type of Posting: Notice of Adoption of Harmonized Standard
Posting Date: 30–Nov–2018
Official Date: 01–Dec–2019
Expert Committee: Excipient Monographs 2
Coordinating Pharmacopeia: Japanese Pharmacopoeia

The revision to the harmonized standard for Anhydrous Dibasic Calcium Phosphate has been approved by the Pharmacopeial Discussion Group (PDG) as described in its PDG sign-off cover sheet. Having reached Stage 4 (former Stage 6) of the PDG process, the Anhydrous Dibasic Calcium Phosphate monograph has been formally approved by the Excipient Monographs 2 Expert Committee in accordance with the Rules and Procedures of the Council of Experts.

The changes from the current Anhydrous Dibasic Calcium Phosphate monograph include:

  • In the beginning of the monograph 
    • Deleted the table of Pharmacopeial Discussion Group Sign-Off Document.
    • Added the statement: “Portions of this monograph that are national USP text, and are not part of the harmonized text, are marked with symbols dotdot.jpg to specify this fact.”
  • Definition
    • Changed from “NLT 98.0% and NMT 103.0%” to “NLT 97.5% and NMT 102.5%” of anhydrous dibasic calcium phosphate.
  •  Assay
    • Changed the Acceptance criteria from “98.0%–103.0%” to “97.5%–102.5%”, based on a request received from PDG.
  • Chloride and Sulfate
    • Clarified the procedure according to the PDG sign-off document and formatted according to USP-NF style.
  • Loss on Ignition
    • Changed the Acceptance criteria from “6.6%–8.5%” to “6.6%–8.7%”, based on the comments received from stakeholders. 
  • Arsenic, Limit of Fluoride, and Packaging and Storage
    • Added the symbols dotdot.jpg , because they are local requirements of USP.
  • Additionally, the monograph has been edited to be consistent with the current USP style.

The Anhydrous Dibasic Calcium Phosphate monograph will be incorporated into and become official with the Second Supplement to the USP 42–NF 37.

Should you have any questions about the Calcium Phosphate Dibasic Anhydrous 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