Sterile filtration: how does it keep our products safe?

In the demanding world of pharmaceutical production and biotechnology, sterile filtration is an indispensable component for both liquids and gases. While it may seem like just one step in the overall production process, it plays a crucial role in ensuring the safety and effectiveness of products. In this blog, we delve into what sterile filtration of liquids entails, why it is an essential link, and how the process works.

What is sterile filtration?

Sterile filtration is the process of removing microorganisms from liquids without compromising the integrity or quality of the product. A filter can only be called 'sterile' if it is capable of retaining 10^7 CFU/cm² of Brevundimonas diminuta under strictly controlled conditions. This high performance level ensures the reliability of the filtration processes we use.

The evolution of filters

The transition from 0.45 μm to 0.22 μm filters reflects significant advancements in our technology. In the 1960s, 0.45 μm filters were sufficient; however, insights from Dr. Frances Bowman at the US-FDA highlighted the necessity for a smaller pore size. This led to the broader adoption of 0.22 μm filters, which now represent the industry standard.

Essential consideration

Material compatibility:
  • Chemical compatibility: It that the filter materials are resistant to the liquid to prevent degradation.
  • Sterilization compatibility: Filters must maintain their integrity during sterilization processes.
  • Adsorption: Limit adsorption to the filter materials to minimize the loss of active ingredients.
Retention:

Choose the right micron size, such as 0.45 or 0.22 μm, for maximum effectiveness.

Flow rate:

This can be predicted using flow/dP data, which is crucial for process optimization.

Capacity:

Understanding how flow/dP behaves during the process helps ensure consistent and efficient filtration.

Step-by-step filtration process

  1. Preparation of the liquid: Start by determining the microbial load and ensure it is as low as possible. If it exceeds NMT 10 CFU/100 ml, use a bioburden-reducing filter to lower the load.

  2. Bioburden-reducing filtration: Use a bioburden-reducing filter to bring the microbial load to an acceptable level before sterilization occurs.

  3. Sterile filtration: Pass the liquid through a 0.22 μm sterile filter. The filter is considered sterile if it can retain 10^7 CFU/cm² of Brevundimonas diminuta ATCC 19146.

  4. Integrity tests: Conduct tests on the sterile filters to confirm their reliability and efficiency. Both redundant and serial sterilization filters undergo these tests to maintain the highest quality standards.

  5. Redundant or Serial Filtration Techniques:
    - Redundant Filtration: Use a second backup filtration system in case the first system fails.
    - Serial Filtration: Use two consecutive sterile filters for added protection, ensuring both filters undergo integrity testing.

  6. Storage and use: Ensure proper storage to prevent recontamination and validate the integrity of the filters used.

Why is sterile filtration so important?

Sterile filtration is more than just a process step; it is a promise to both producers and consumers that their products are safe and reliable. It ensures that essential medicines and vaccines reach their destination without compromise. By continuously innovating and improving our filtration methods, we maintain compliance with the stringent standards required by the modern pharmaceutical industry. In an era where safety and hygiene are paramount, sterile filtration is essential for protecting the health and safety of everyone.

Do you need help with your sterile filtration process?

Sterile filtration is not just a step in the production process; it is a fundamental pillar that ensures medications and other crucial products are safe and effective. By leveraging the right technologies and materials, producers can trust that their products meet the highest standards of purity and safety.


For more information about sterile filtration or if you have questions about our extensive range of products, click the button below to get in touch with us!