Type of Posting: Notice of Adoption of Harmonized Standard

Posting Date: 25–Sep–2015

Official Date: 01–Aug–2016

Expert Committee: Monographs—Excipients

Coordinating Pharmacopoeia: European Pharmacopoeia

The new harmonized standard for Isomalt has been approved by the Pharmacopeial Discussion Group (PDG) as described in its PDG sign-off cover sheet. Having reached Stage 6 of the PDG process, the Isomalt monograph has been formally approved by the Monographs—Excipients Expert Committee in accordance with the Rules and Procedures of the Council of Experts.

On April 1, 2015 USP revised General Notices: Section 5.60.30 Elemental Impurities in USP Drug Products and Dietary Supplements via a Revision Bulletin which established January 1, 2018 as the new date of applicability of General Chapters <232> Elemental Impurities—Limits and <2232> Elemental Contaminants in Dietary Supplements. This new date is intended to align the implementation of General Chapter <232> more closely with that of the ICH Q3D Guideline for Elemental Impurities. The implementation of General Chapters <232> and <2232> will coincide with the removal of all references to General Chapter <231> Heavy Metals from monographs and General Chapters in the USP–NF. 

Accordingly, the reference to General Chapter <231> Heavy Metals in this monograph was omitted with an official implementation date of January 1, 2018, as indicated in the recently revised General Notices. For further details see General Chapter <231> Heavy Metals and Affected Monographs and General Chapters Revision Bulletin.

Changes from the existing USP–NF monograph include:

  • In the beginning of the monograph,
    • Added the statement: “Portions of this monograph that are national USP text, and are not part of the harmonized text, are marked with symbols to specify this fact.”
  • Chemical Information.
  • Added chemical structure. Revised chemical name to clarify that Isomalt is a mixture. Synonyms are also listed.
  • Added the temperature for detector: “Refractive index, maintained at a constant temperature (40° for example)”.
  • Changed the column temperature from “80 ± 1°” to “80 ± 3°” in accordance with Pharmacopeial Discussion Group (PDG) text.
  • Deleted the Heavy Metals test. The official implementation date for this revision is January 1, 2018.
  • Replaced the previous method with the harmonized method
  • In the sample solution, specified the concentration of acetic acid and reworded it; revised the 25 mL of a mixture from “6 mL of hydrochloric acid and 94 mL of water” to “hydrochloric acid and water (6:94)”.
  • Changed Acceptance Criteria from “7%” to “7.0%” in accordance with PDG sign-off document.
  • Specified the heating temperature (40-50°) in sample solution preparation.
  • Assay
  • Heavy Metals
  • Limit of Nickel
  • Reducing Sugars
  • Water Determination
  • Conductivity
  • Added the symbols to the non-harmonized attributes or local requirements – Identification Test A (Thin-layer chromatography) and Packaging and Storage.

Additionally, the monograph has been edited to be consistent with the current USP style.

The Isomalt monograph will be incorporated into and become official with the First Supplement to USP 39–NF 34. The official implementation date for the omission of the Heavy Metals test is January 1, 2018.

Should you have any questions about the Isomalt monograph, please contact 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