<1174> Powder Flow

Type of Posting: Notice of Adoption of Harmonized Standard

Posting Date: 28-Apr-2023

Official Date: 1-May- 2024

Expert Committee: Excipient Test Methods

Coordinating Pharmacopeia: European Pharmacopoeia

A revision to the harmonized standard for <1174> Powder Flow has been approved by the Pharmacopeial Discussion Group (PDG) as described in its PDG Rev. 1 sign-off cover sheet. Having reached Stage 4 (former Stage 6) of the PDG process, the general chapter of <1174> Powder Flow has been formally approved by the USP Excipients Test Methods Expert Committee in accordance with the Rules and Procedures of the 2020-2025 Council of Experts.

Major changes from the existing USP–NF General Chapter include:

  1. In the beginning of the chapter, added the statement: "This general chapter has been harmonized with the corresponding texts of the European Pharmacopoeia and/or the Japanese Pharmacopoeia. Portions of this chapter that are national USP text, and are not part of the harmonized text, are marked with symbols (⧫⧫) to specify this fact."
  2. In the Compressibility Index and Hausner Ratio section, applied the terms of "untapped bulk density" and "tapped bulk density" to align with Bulk Density of Powders 〈616〉.
  3. In the Flow Through an Orifice section, introduced the term "arching diameter".
  4. Updated the Shear Cell Methods section, including major updates to the "Methods for Shear Cell" section. Added a reference to Shear Cell Methodology For Powder Flow Testing 〈1063〉, as a USP local text.
  5. For consistency, replaced “material(s)” with “powder(s)” at the appropriate places throughout the chapter.
  6. Many other description changes have been made in the chapter.

Additionally, minor editorial changes have been made to update the chapter to current USP style.

General Chapter <1174> Powder Flow will become official from May 1, 2024.

Should you have any questions, please contact Dr. Tong (Jenny) Liu ((240) 221-2072 or jyl@usp.org). For any questions about the PDG and its processes, please see Pharmacopeial Harmonization Group or contact Richard Lew at (240-221-2060 or rll@usp.org).

Revision History