What does PUPSIT mean?

PUPSIT is critical for the safety and compliance of sterile filters. But what does that actually mean, and why does it matter?

Keep reading as we break down everything you need to know about this method of testing, and how ALLpaQ plays a role in safe and sterile pharmaceutical solutions.

What is PUPSIT?

PUPSIT stands for Pre-Use Post-Sterilisation Integrity Testing.

Essentially, PUPSIT refers to testing for defects that may have occurred during sterilisation or assembly of a sterile filter. 

It’s a strong regulatory expectation for products that sit under EU GMP Annex 1, requiring rigorous testing before the product is processed and routinely after use.

How does PUPSIT work?

There are numerous ways to test the integrity of a filter, including:

• Bubble point testing – The filter is wetted while gas pressure increases until bubbles begin to appear. If a bubble appears too easily, it can indicate an oversized pore, tear, or defect.
• Diffusive flow testing – Tests how much gas passes through a wetted filter at a constant pressure. It’s expected to see a small amount flow through, but too much is a sign of a defect.
• Water intrusion testing – Ensures that hydrophobic gas filters are watertight, especially for gas filtration, where liquid ingress is an issue.
• Pressure hold testing – Monitors whether pressure remains stable over time. If not, it could point to a leak, damage, or faulty connection. It’s sometimes also referred to as pressure decay testing.

The most appropriate method of testing usually depends on the product and how it is used.

Why does filter integrity testing matter?

PUPSIT is vital to ensure that sterile filters can conduct their purpose thoroughly, as flaws in filters can lead to contamination, allowing particles or microorganisms to slip through into the final product. In sectors such as the pharmaceutical industry, this breach could have potentially life-threatening consequences.

Regular testing also means that batches can be released with confidence, while processes are repeatable for controlled and consistent product quality. What’s more, with PUPSIT, you can detect detrimental issues that are potentially invisible to the naked eye and could otherwise easily be missed.

How does ALLpaQ support the PUPSIT process?

ALLpaQ’s bioprocessing containers and single-use bags are compatible with the PUPSIT process – providing a sterile downstream containment solution for your storage and transportation needs. Our products are also fully customisable to your requirements – whether that’s regarding bag format, port configuration, or process specifications – without disrupting your existing fluid management systems.

We work alongside specialist filtration assembly manufacturers, such as PharmNXT,  to ensure compliance between our products and PUPSIT systems – meaning customers can be assured that their setup, storage, and transportation system works seamlessly as one.

Ready to discover how our bioprocessing containers can help your business? Get in touch today.

Author

Andrew

Gillespie

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