Essential Guide to Liquid Filtration in Pharmaceutical Production

Talk to us

Liquid filtration in pharmaceutical production is the process of removing impurities and microorganisms from a pharmaceutical liquid through a pharmaceutical filter.

Optimizing the filtration process and selecting the best filters saves labor, equipment and the time and costs required for filter replacement.

Do you know which filters are used for liquid filtration in the pharmaceutical production process? Next, we will show you the types of filters needed in pharmaceutical processing and how to choose the right filtration system.

Pharmaceutical Production

Why filters are needed in the process of manufacturing pharmaceutical liquids

Pharmaceutical filters separate impurities and microorganisms in pharmaceutical solutions through a filter medium. The filtering medium is usually a microporous material such as filter paper, filter membrane or filter cartridge.

When the medicinal liquid passes through the filter medium, the impurities and microorganisms are retained on it, while the pure medicinal liquid passes out.

The main functions of the medicinal liquid filter are as follows:

Removal of impurities: including suspended matter, sediments and particles, etc., to ensure the purity and stability of the medicinal solution.

Remove microorganisms: such as bacteria, viruses and fungi, etc., to ensure the sterility and safety of the pharmaceutical solution.

Improve product quality: Enhance the market competitiveness and credibility of the product by improving the purity and quality of the medicinal liquid.

Protect equipment: prevent damage and contamination of equipment by impurities and microorganisms, prolong the service life and performance of equipment.

manufacturing pharmaceutical liquids

When to use liquid filtration in pharmaceutical processes

When to use liquid filtration in pharmaceutical processes

Liquid filtration and separation is a requirement for several processes in pharmaceutical manufacturing.

Some of the applications that use liquid filtration include:

Clarification and pre-filtration to remove solid impurities, insoluble powders and particles to ensure a high-quality end product and protect downstream equipment
Solvent filtration in active pharmaceutical ingredient (API) manufacturing
Formulation and powder blending of various combinations of substances, including active pharmaceutical ingredients, to produce final drug compounds
Reduction of bioburden, reducing particles or bacteria that reach the final sterilization filtration stage
Sterile filtration of final products
Sterile water for injection for diluting and dissolving drugs

How to choose a medicinal fluid filter?

What is Tangential Flow Filtration

Determine the characteristics of the liquid

The characteristics of the liquid being filtered determine the material you choose for your filter cartridge. The viscosity, chemical composition, temperature, pH and concentration of the fluid will affect the effectiveness and efficiency of the filter. Chemical compatibility is also an important factor in determining the best type of filter media.

For example, if the fluid is highly abrasive or corrosive, PTFE or polypropylene media is best. More viscous liquids may adsorb proteins, so to ensure low protein precipitation rates, choose PVDF membranes or other similar media. If you are unsure of the filter that is best suited for the medicinal fluid you are working with, contact the filtration experts at Sanitek.

Determining Filtration Requirements

When we choose a pharmaceutical liquid filter, we need to consider things like flow rate and particle size. All liquid filters for pharmaceutical manufacturing are available in microns and efficiency levels. Liquid filters also have different efficiency levels, usually categorized into nominal and absolute filtration levels.

A nominal filtration level means that 75-80% of particulate matter will be captured at that particular micron level. Absolute filtration ratings capture 99% of the contaminants near or above the listed micron rating. Typically, nominal filters will be used upstream in the filtration process to capture larger particles, while absolute filters will be used at the end to capture smaller contaminants.

One additional point to note is that higher filtration accuracy is not always appropriate. Often higher precision filters will suffer some degree of damage to the filter due to the small filter particles and the more stringent requirements of pharmaceutical filtration, thus affecting its service life.

Filter Series Type
Ultrapure PP Filter Cartridge Polypropylene (PP) Normal
Stery PS Filter Cartridge Polyethersulfone (PES) Sterilization
GasFlow EPTF Filters Polytetrafluoroethylene (PTFE)high-temperature Gas Sterilization
CNS Filter Cartridge Nylon66 Sterilization
Stery PVF Cartridge Filter Polyvinylidene fluoride film (PVDF) Sterilization

Selecting a Filter Type

Once you have determined the fluid and filtration requirements, you are ready to select the filter type. There are several types of filters to choose from, including depth filters, capsule filters and pleated membrane filters.

When laboratories study pharmaceutical solutions, they usually use capsule filters, which are small, easy to use, and can be spot-cleaned and steam-sterilized at high temperatures, which also ensures the purity and stability of the solution in a single-use.

When the pharmaceutical factory produces the drug solution, it usually uses the sterilization filter, which can ensure the consistency and effectiveness of filtration between batches.

In general, the biopharmaceutical industry will widely use several filters that can withstand stringent cleaning (CIP) and sterilization (SIP), Sanitek provides the corresponding filtration products, if you are not sure of the type of filter you need, please contact our technical experts to help you.

Compatibility with Filter Housings

Compatibility with Filter Housings

The selection of the gasket/O-ring and end cap configuration determines the compatibility of the filter element with the filter housing. The most important considerations when selecting a gasket/O-ring are chemical compatibility, temperature, and service life.

Buna-N (nitrile butadiene) is a standard option that provides a good seal for many fluids but is susceptible to more aggressive chemicals. However, it is resistant to petroleum-based fuels.

EPDM (or ethylene propylene) has excellent ozone resistance and is typically used in FDA-regulated processes in the pharmaceutical industry to hold shape and maintain it for longer periods.

Silicones can hold their shape and seal for long periods. They are effective above 400°C and across a wide range of chemicals.

Polytetrafluoroethylene or polytetrafluoroethylene (PTFE) gaskets are extremely abrasion and corrosion resistant. They offer optimum chemical compatibility in the process of pharmaceutical filtration.

Viton or fluoroelastomer has excellent sealing properties and works well with gases, fuels and many organic chemicals. It performs well at high temperatures, but low temperatures can cause hardening and negatively affect the seal.

Liquid Filter Cost Considerations

Finally, the cost of the filter needs to be considered, which includes materials and costs associated with maintenance and replacement. Capsule filters are single-use Capsule filters suitable for filtration of small amounts of medicinal liquids, with little residue and loss, and are easy to install.

They can be sterilized off-line. Cartridge filters are low cost and can be sterilized in-line or off-line. According to the filtration requirements, combined with the previous items, considering the budget can choose different filtration programs.


Filtration is a basic requirement in pharmaceutical manufacturing, and appropriate filters are used at multiple points in the liquid filtration process for pharmaceuticals.

By considering the type of liquid, filtration requirements, filter type, filter material, existing system fit and cost, you can select a filter that meets your specific needs and provides efficient and cost-effective filtration.

Sanitek offers a full line of filtration products for the pharmaceutical industry, including capsule filters, cartridge cartridges, lenticular filter, filter housings and more. If you are unsure of the type of filter you need, please contact our technical experts and we will assist you within 24 hours.

All Categories

Wanting more information about Sanitek? Contact us now!

Contact Us

Let’s help you find solution suites your needs.

Explore more how we can solve your toughest problems in critical filtration.

Consult with an Expert

error: Content is protected !!