USP Chapter 41 (USP41) Weighing Requirements for Balances

What is the USP?

The United States Pharmacopeia (USP) is a scientific organisation responsible for setting the official public standards for drugs and drug products in the USA. The USP drug standards are used in over 140 countries and include identity, strength, quality and purity of substances manufactured. The Food and Drug Administration (FDA) are responsible for their enforcement.

You can find out more about The USP on their website.

What is The USP Chapter 41 (USP41)?

Chapter 41 of the USP standards is titled ‘balances’ and refers to the mandatory requirements for the accurate weighing of materials using a balance.  On 1st December 2013, the new regulations of USP Chapter 41 went into effect and this chapter is mandatory in a Pharmaceutical Quality Control (QC) laboratory, where weighing is a fundamental step in almost every workflow.

The weighing of a sample is typically the first step in an analytical procedure, and therefore has the potential to propagate through the process and cause the inaccuracy of the final result. Therefore, the USP has set official requirements for balances in order to reduce uncertainties within analysis that could be detrimental to human health.

The mandatory Chapter 41 states that a balance should be properly calibrated over the operating range. Repeatability and accuracy requirements are defined, with acceptance limits and permissible test weights. The White Paper ‘Weighing According to US Pharmacopeia’ explains the requirements in more detail.

You can download the USP41 here: USP41

What is The USP Chapter 1251 (USP1251)?

The informational Chapter 1251, ‘Weighing on an Analytical Balance’ is also relevant. It provides detailed guidance on the strategy for qualification and operation of balances, however this is only a recommendation and therefore not enforced by the FDA.

The chapter covers installation and operational qualification (IQ/QQ), performance qualification and balance checks, minimum weight and balance operation.

You can download the USP1251 here: USP1251

How can Precisa assist with USP requirements?

At Precisa we support pharmaceutical manufacturers to implement the USP weighing regulations through a number of ways.

Precisa’s higher end balances for analytical (0.1mg) and Semi Micro (0.01mg) readability are also specifically designed to accommodate many of the USP41 requirements. The HA/HF models of our 390 Series have automatic calibration if environmental conditions change, such as humidity, pressure or temperature. They also have user log in, audit trail and admin functions to restrict use and monitor the results generated on an instrument.

Furthermore, our 321 LT balances for the M,C,D ranges are also in alignment with USP41 requirements. These balances have capacities of >1000g in some cases with 0.001g, 0,01g and 0.1g readability. Our LT1220M displays a green, amber or red light which acts as a visual alarm if the amount being weighed is outside the tolerance, which is ideal for the check weighing of pharmaceutical products.

Get in Touch

We hope you have found this article about the USP weighing requirements informative. If you would like assistance with conforming to the guidelines or to find out more information, please do not hesitate to get in touch with a member of our team today.

Why not read our recent article to find out more about how to conform to Good Laboratory Practice.

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