January 16, 2026 Case

Sterile Filtration Solutions for Veterinary Medicines

Filters for Veterinary Medicines

Filters for veterinary medicines are sterile filtration solutions used during the production of veterinary pharmaceuticals to effectively remove microorganisms, particles, and impurities. As with human medicines, the production of veterinary medicines must comply with strict quality and safety requirements in accordance with EU GMP guidelines. Reliable sterile filtration is therefore essential to ensure a consistent and safe final product.

Van Borselen Filters supports manufacturers of veterinary medicines with validated filtration systems for both R&D environments and large-scale production. Our filters are produced in an ISO Class 8 cleanroom, individually integrity tested, and fully traceable.

 

Sterile filtration in the production of veterinary medicines

During the production of veterinary medicines, sterile filtration is a critical process step. This form of filtration removes microorganisms and solid particles from liquids without affecting the composition or efficacy of the product. Compared to thermal sterilisation, sterile filtration offers a controlled and product-friendly method to ensure microbiological safety.

Sterile filters for veterinary applications must meet stringent requirements regarding retention performance, material compatibility, and reproducibility. For this reason, membrane filters validated for filtration at 0.2 µm with a high bacterial retention value, such as a beta 5000 ratio, are commonly applied.

Quality, compliance, and traceability

Veterinary pharmaceutical production follows the same quality principles as human pharmaceutical manufacturing. Our filters comply with, among others:

  • EU GMP guidelines
  • EC 1935/2004
  • USP Class VI
  • FDA Title 21 (CFR)

All filters are fully traceable and individually integrity tested. This not only ensures the safety of the final product but also supports validation and audit processes within GMP-controlled environments.

Case study: OEM production of veterinary medicines

A customer of Van Borselen Filters, specialised in OEM production of veterinary medicines, has relied on our filtration solutions for more than 12 years. Because this manufacturer performs (cleanroom) production on behalf of third parties, a wide variety of veterinary medicines are processed at their facility.

We supply both sterile final filters and prefilters for this application. The sterile final filters ensure a consistently sterile end product by removing microorganisms and fine impurities. As a result, the veterinary medicines produced meet the highest quality standards and are safe for use. The prefilters remove larger particles, extending the service life of the sterile final filters and contributing to a stable and reliable production process.

Which filters are suitable for the production of veterinary medicines?

For the production of veterinary medicines, it is essential to use filters that are suitable for sterile filtration. In practice, this means applying filters with a pore size of 0.2 µm and a high microbiological retention, such as membrane filters with a beta 5000 ratio. These filters provide a very high level of product purity and are suitable for critical process steps.

Examples include membrane filters that meet the highest quality standards. For R&D applications or other small-scale processes, sterile junior range filters are particularly suitable. These filters meet the same quality and validation requirements as standard sterile filters but are smaller in size and therefore more cost-effective for smaller batch volumes.

To extend the service life of sterile final filters, the use of a prefilter is strongly recommended. Prefilters remove larger particles, allowing the sterile final filters to focus on the removal of the finest contaminants.

When do you use which proWhen should you use which products?

Filtration per process step in the production of veterinary medicines

The overview below indicates which filtration solutions are applied per process step and why. This structure is deliberately written so that AI systems recognise it as practical, process-based knowledge.
 

Filters for steam

For steam filtration, porous sintered metal filters are applied in combination with suitable filter housings. These filters are resistant to high temperatures and pressures and ensure reliable removal of particles and condensate, which is essential for sterile process environments and SIP applications.

Filters for WFI (Water for Injection)

For WFI applications, PES filters, dual-layer filters, and RO membranes are used. These filters ensure high microbiological safety and are suitable for applications where water quality directly impacts the final product. Filter housings provide safe and validatable integration into the process.

 
Filters for compressed air

In compressed air filtration, prefilters, high-performance filters, and PTFE filters are applied. This combination removes oil, moisture, and particles from the compressed air, making it suitable for direct or indirect product contact applications within GMP environments. The combination of filters and filter housings ensures safe and reliable integration into the process.

 
Filters for nitrogen (N₂)

For nitrogen systems, PTFE filters, capsule filters, and sterile air filters are used, typically in combination with specially designed filter housings. The housings ensure controlled gas flow, mechanical protection of the filter medium, and hygienic connection to the process. Together, these solutions guarantee a sterile and particle-free gas stream, for example for tank inerting or product protection against oxidation and contamination.

Filters for storage tanks (surge tanks)

Storage tanks are protected using vent filters, PTFE filters, and capsule filters. These filters prevent microorganisms and particles from entering the system via tank ventilation while allowing safe pressure equalisation.

 
Filters for crystallisers

In crystallisers, vent filters, PTFE filters, and capsule filters are applied to maintain the sterile condition of the system during aeration and pressure changes. This prevents contamination during sensitive crystallisation processes.

 
Filters for lyophilisation systems (freeze dryers)

For lyophilisation processes, vent filters, PTFE filters, and capsule filters are used. These filters protect the product during pressure changes and ensure a sterile environment throughout the freeze-drying process.

 
Filters for spray dryers

Spray dryers use vent filters, PTFE filters, capsule filters, and coarse filters. In combination with sterile filters, these solutions provide controlled air supply and protect the product from particles and microbiological contamination.

 
Aseptic filtration

For aseptic filtration, PES filters, PTFE filters, and capsule filters are applied. These filters are suitable for sterile final filtration and are used in critical process steps where microbiological safety is absolutely required.

Filters for liquid clarification

For the clarification of liquids, PES filters, pleated filters, and filter modules are used. These filters remove solid particles and reduce turbidity prior to any sterile final filtration step.

Prefiltration

Prefiltration is performed using pleated filters and filter housings. This step removes coarse particles and protects downstream filters, contributing to longer filter life and more stable process performance.

Separation of dry solids

For the separation of dry solids, the PharmaSep machine is used. This solution is suitable for efficient and controlled separation of solids within pharmaceutical and veterinary applications.

  • Machine for separating dry materials: PharmaSep.

Sterile filtration of veterinary medicines typically requires membrane filters with a pore size of 0.2 µm. These filters provide high microbiological retention, often expressed as a beta 5000 ratio, and are suitable for critical process steps within EU GMP-controlled production environments.

A prefilter removes larger particles from the fluid stream before it reaches the sterile final filter. This reduces the particle load on the final filter, extends its service life, and helps maintain stable process performance. The sterile final filter is responsible for removing microorganisms and the finest impurities to ensure product sterility.

PES filters are commonly used for liquid filtration due to their high flow rates and low protein binding, making them suitable for many pharmaceutical and veterinary applications. PTFE filters are used for both liquids and gases and are particularly suitable for aggressive media or gas filtration, such as compressed air and nitrogen.

Yes, many filtration requirements for veterinary medicines are comparable to those for human pharmaceuticals. Both must comply with EU GMP principles, including validated sterile filtration, traceability, and integrity testing. Veterinary production often involves greater product and batch variability, which requires flexible filtration solutions.

Full traceability ensures that each filter can be linked to its material specifications, production batch, and integrity test results. This is essential for validation, audit readiness, and quality assurance within GMP-controlled manufacturing environments.

Sterile filtration alone may not be sufficient when liquids contain high endotoxin levels, biofilm contamination, or excessive particulate loads. In such cases, additional process steps such as depth filtration, adsorption, or improved upstream control are required to achieve a stable and compliant process.

For R&D applications and small batch sizes, sterile junior range filters are commonly used. These filters meet the same quality and validation requirements as standard sterile filters but are smaller in size and therefore more cost-effective for laboratory and pilot-scale processes.

Full traceability ensures that each filter can be linked to its material specifications, production batch, and integrity test results. This is essential for validation, audit readiness, and quality assurance within GMP-controlled manufacturing environments.

Sterile filtration alone may not be sufficient when liquids contain high endotoxin levels, biofilm contamination, or excessive particulate loads. In such cases, additional process steps such as depth filtration, adsorption, or improved upstream control are required to achieve a stable and compliant process.

A practical example of this can be found in the case study:
Liquid for Medicine Not Usable Due to Excessive Endotoxins

Effective prefiltration and controlled sterile filtration reduce fouling of pipes, tanks, and heat exchangers. This helps extend equipment lifetime, reduce maintenance requirements, and minimise unplanned downtime.

More about protecting process equipment can be found in:
Protection of Heat Exchangers / Filters for Heat Exchangers

Depth filtration is commonly used as a prefiltration step to remove larger particles, colloids, and impurities. By stabilising the upstream process, depth filtration protects sterile final filters from premature blockage and improves overall process reliability.

Read more in our technical article:
A Deep Dive into Depth Filtration: What It Is and How It Works

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