Implementing USP 2022 Updated Formulas in OpenLab CDS

**USP chapter 621 updates that are effective December 1, 2022**

Introduction

The United States Pharmacopeia (USP), chapter 621 for Chromatography will be updated with changes that are effective December 1, 2022. Relevant to chromatography data systems are the following changes:

- Resolution is based now on the peak width at half of the peak height.
- Plate number is based now on the peak width at half of the height.
- Signal-to-noise is now calculated using a range of noise 20 times the width at half-height of the peak.

Users of OpenLab CDS can adopt the new formulas as described in this article.

Calculating the New Formulas in OpenLab CDS

**Resolution (Rs)**

The new formula is the same as EP or JP so users of earlier versions can simply choose EP or JP Resolution.

Then, in the Report Template Editor, rename the column to Resol. USP 2022:

**Plate Number (N)**

The new formula is the same as ASTM, EP, and JP so users of earlier versions can simply choose one of these. Again, the parameter can be renamed in the reports.

**Signal-to-Noise Ratio (S/N)**

The new USP method measures noise across 20 times the peak width at half height where the previous method used only 5 times the peak width. In OpenLab CDS, the Noise range setting of Automatic uses a range of 20x the peak width at half height.

Note if you are using the previous USP method, the updated USP states that a range of only 5 times the half-height peak width is permitted when the chromatography does not allow the wider range.

Scope

This article applies to versions 2.2 through 2.7 of OpenLab CDS.

References

The calculation formulas used by OpenLab CDS can be found in the OpenLab Help & Learning online at System Suitability Calculations

Notice of Adoption of Harmonized Standard (usp.org)

**Change Log**

29Sep 2022 11:54 PDT: Initial version