Factors to consider when selecting a sterilizing filter

When it comes to removing mycoplasma, the manufacturer and validation testing will determine whether a smaller pore size of 0.1 or even 0.03 microns is necessary. In cases where endotoxin removal is also required, utilizing positively charged filters becomes essential.

How to Validate the Sterilizing Filters?

To ensure the effectiveness of sterilizing filters, they undergo thorough validation procedures that adhere to the ASTM F 838-15(ae1) protocols for evaluating bacterial retention in liquid filtration filters. During these validation tests, the filters are challenged with a minimum of 107 organisms per cm2 of filter media. Remarkably, our filters demonstrate a superior removal rate exceeding 7 logarithms when exposed to the specified organisms.

Moreover, the pore sizes of our filters, such as 0.03μm, 0.10μm, and 0.22μm, have been extensively validated and meet the stringent criteria set forth by the FDA for sterilizing grade filters. The validation process involved the use of specific organisms, namely Acholeplasma laidlawii for 0.03μm and Brevundimonas diminuta for both 0.10μm and 0.22μm. By successfully meeting the FDA’s definition of sterilizing grade filters, we can assure the utmost level of filtration efficiency and protection against microbial contamination.

How to Validate the Sterilizing Filters?

To ensure the effectiveness of sterilizing filters, they undergo thorough validation procedures that adhere to the ASTM F 838-15(ae1) protocols for evaluating bacterial retention in liquid filtration filters. During these validation tests, the filters are challenged with a minimum of 107 organisms per cm2 of filter media. Remarkably, our filters demonstrate a superior removal rate exceeding 7 logarithms when exposed to the specified organisms.

Moreover, the pore sizes of our filters, such as 0.03μm, 0.10μm, and 0.22μm, have been extensively validated and meet the stringent criteria set forth by the FDA for sterilizing grade filters. The validation process involved the use of specific organisms, namely Acholeplasma laidlawii for 0.03μm and Brevundimonas diminuta for both 0.10μm and 0.22μm. By successfully meeting the FDA’s definition of sterilizing grade filters, we can assure the utmost level of filtration efficiency and protection against microbial contamination.

Flow Rate, Batch Size, Filter Longevity

When selecting the ideal filtration solution, it is essential to consider various factors beyond fluid properties. These include the desired flow rate, batch size, and expected filter lifespan. While these aspects might not hold much importance in situations with low flow or volume requirements, they become vital considerations when dealing with more demanding applications.

Typically, a single-layer filter will deliver the highest flow rate per cartridge. However, depending on the aforementioned fluid characteristics, this choice may lead to premature fouling and a shortened service life of the filter.

Integrating an additional prefilter into the filtration system will decrease the flow rate per cartridge. Nevertheless, this compromise can be justifiable if it results in an extended service life that meets the requirements of the batch size. Moreover, the reduced flow rate can be compensated by using longer cartridges or capsules, such as 20″ or 30″, instead of the standard 10″. Alternatively, multiple cartridges can be utilized within the same housing.

Integrity Testing & Pre-sterilization

Conversely, cartridge filters are typically not pre-sterilized. This is attributed to the fact that regardless of the handling of the packaging, the sterilization efficacy is compromised upon its opening.

There are various methods used to pre-sterilize filters, with the most common being gamma radiation carried out after packaging.

Sanitek Sterilizing Filter Options

Stery PS HT Cartridge Filter: This filter features a double-layer membrane design, with a high capacity prefilter positioned in front of the sterilizing layer. This setup enhances the filter’s lifespan in situations where there is a high load of particles.

Stery PS Capsule Filter&Stery EPS Capsule Filter: When there is a need to remove endotoxin, a positively charged PES (polyethersulfone) material is used.

Ultrapure NY Capsule Filter: Positively charged Nylon 6,6 is utilized for endotoxin removal in cases where compatibility with PES is a concern.

Stery PTF Filter&Stery PTF Capsule: These are used for sterilizing process gas applications and tank vents.

Conclusion

When choosing the ideal sterilizing filter, it is crucial to carefully evaluate your filtration goals and the characteristics of your process fluid. It is also important to identify any issues with your current using filters. In many cases, a basic process assessment will provide the necessary solution. However, if needed, testing can be conducted to optimize the filter(s) for your specific application.

With more than a decade of filtration expertise, Sanitek specializes in the development, manufacturing, supply, and servicing of cutting-edge microfiltration products on a global scale. We offer high-performance products and comprehensive technical support services tailored for critical applications.