Lactose 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: USP

A harmonized standard for Lactose 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 Lactose 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:

  • Changed the Definition to state chemical name, consistent with PDG sign off and Anhydrous Lactose monograph.
  • Changed temperature in Residue on Ignition from 600 plus/minus 25 to 600 plus/minus 50 to be consistent with PDG sign off and harmonized ROI chapter.
  • Added “VS” to the 0.1 N sodium hydroxide for clarity in Acidity or Alkalinity. Also, changed requirement from “to produce a red color” to “to produce a pink or red color”, consistent with the sign off.
  • Removed Identification Test C per vote by the Monographs-Excipients Expert Committee. It was determined that this method was not necessary with ID A and B. USP can remove the test as it is listed as a local attribute.
  • The following tests are labeled as USP national text and are non-harmonized: ID B, Heavy Metals, Microbial Enumeration, Tests for Specified Microorganisms, Loss on Drying, Packaging and Storage, Labeling, Reference Standards.

The Lactose Monohydrate monograph will be incorporated into and become official with Supplement 1 to USP 35–NF 30.

**Should you have any questions about the Lactose 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 remove ID C because it is redundant to ID A. This deletion was missing in the initial posting of the PDF monograph.