Magnesium Stearate

Type of Posting: Notice of Adoption of Harmonized Standard

Posting Date: 25–Sep–2015

Official Date: 01–Aug–2016

Expert Committee: Monographs—Excipients

Coordinating Pharmacopeia: USP

The correction to the harmonized standard for Magnesium Stearate 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 Magnesium Stearate monograph has been formally approved by the Monographs—Excipients Expert Committee in accordance with the Rules and Procedures of the Council of Experts.

Changes from the existing USP–NF monograph include:

  • For the following three limit tests by graphite furnace atomic absorption (GFAA) spectroscopy analysis, the correlation coefficient (r) of the standard additions plot was changed from “must be at least 0.995” to “must be at least 0.99”.
    • Limit of Cadmium
    • Limit of Lead
    • Limit of Nickel
  • NMT” was also added to the acceptance criteria for the three limit tests above.
  • The symbols were added to the non-harmonized attribute Microbial Enumeration Tests and Tests for Specified Microorganisms.

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

The Magnesium Stearate monograph will be incorporated into and become official with the First Supplement to USP 39–NF 34.

Should you have any questions about the Magnesium Stearate 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