In the pharmaceutical industry, filtration is an important process used in the manufacture of active pharmaceutical ingredients (APIs) and finished dosage form formulations. The purpose of filtration in the pharmaceutical industry is to remove impurities in the product and ensure that the API or finished product meets the specified quality standards.

Pharmaceutical Industry

The pharmaceutical industry uses many different types of filtration systems, each with its own advantages and disadvantages. The type of filtration system used depends on many factors including the nature of the product, the desired quality of the finished product, and the manufacturing process.

In this article, we will take a closer look at the different types of filtration systems used in the pharmaceutical industry and their applications.

Why Filters Are Needed in Pharmaceuticals

In the pharmaceutical industry, the process of filtration and separation is crucial. The quality and effect of the product need to be controlled by filtration during its production process. If the filtration system is not appropriate, valuable products will be lost during the production process.

The pharmaceutical industry pays particular attention to product safety issues, which are also very important in the production of its drugs. The highest standards must be maintained for the manufacture of pharmaceuticals, with no room for error. The filtration systems and filters used in its production process must be able to effectively filter corrosive fluids and impurity particles.

filtration for the pharmaceutical industry

Filtration Methods Used in the Pharmaceutical Industry

Manufacturers in the pharmaceutical industry often choose different methods of filtering their media according to their individual needs. It is important to note that all filtration methods involve the use of porous membranes to filter particulate matter from liquids or gases.

Surface Filtration

In surface filtration, a membrane with pores of a specified size is used, enabling particles of that size to pass but capturing anything larger. With this method, undesirable particles are directly targeted by the filter. It is also known as membrane filtration since it occasionally employs a porous membrane.

Depth Filtration

Similar to surface filtration, depth filtration eliminates particles from deeper into the water, as the name implies. When handling solutions, Pharmaceutical professionals typically take this way. In order to remove suspended particles from the fluid or gas, this method uses a filter based on cellulose to filter those particles.

Crossflow/Tangential Flow Filtration

Biomolecules are separated and purified using this filtration method. Although it is more frequently utilized in other industries than pharmaceutical manufacturing, such as microbiology, it is nevertheless worth mentioning. It can concentrate sample solutions, harvest cell suspensions, and clear fermentation broths.

Cross filrtation


Nanofiltration is a kind of tangential flow filtration, which mainly uses membranes with a pore size of 1 nanometer or less for filtration. The process involves applying relative pressures no greater than that required for tangential flow filtration, making the entire process more cost-effective by reducing energy intensity.

Filter Types for Pharmaceutical Processing

Pharmaceutical processing requires a high level of filtration to ensure the safety and efficacy of the drugs produced. There are several types of filters used in pharmaceutical processing, including:

Membrane filters: These filters use a membrane to remove particles and microorganisms from the liquid. They are commonly used for sterile filtration, virus removal, and clarification of solutions.

Membrane filters

Depth filters: These filters use a thick layer of filter media, such as cellulose or activated carbon, to trap particles and microorganisms. They are commonly used for pre-filtration and clarification of solutions.

Cartridge filters: These filters consist of a cylindrical cartridge filled with filter media, such as activated carbon or synthetic fibers. They are commonly used for pre-filtration, clarification, and removal of microorganisms.

cartridges filters

Bag filters: These filters use a bag filled with filter media, such as nylon or polyester, to trap particles and microorganisms. They are commonly used for pre-filtration and clarification of solutions.

bag filters

Syringe filters: These filters are small, disposable filters that are attached to a syringe to filter small volumes of liquid. They are commonly used for sterilization of small volumes of liquids.

Self-cleaning filters: These filters are becoming increasingly popular in pharmaceutical processing. It automatically removes contaminants from the filter element, reducing downtime and increasing efficiency. They are commonly used for high-volume applications that require continuous filtration.

self-cleaning filters

Where to Use Liquid Filtration in the Pharmaceutical Process

Pharmaceutical production has multiple processes and each process requires liquid filtration and separation. Below is the part of applications that liquid filtration is used in:

  • Used for clarification and pre-filtration to remove solid impurities and particles
  • Solvent Filtration Treatment During Active Pharmaceutical Ingredient(APIs) Manufacturing
  • Formulation and powder mixing of various combination substances i.e. active pharmaceuticals
  • Removal of particles and bacteria reaching the final sterile filtration stage
  • Sterile Filtration of Final Products
  • Filtration treatment of sterile water for injection

The above are only some part of applications because many pharmaceutical processes require very thorough and demanding filtration of liquids. It is important to understand the filtration systems and filter types commonly used in the industry.

Liquid Filtration in the Pharmaceutical Process

Selecting the Right Filter for Pharmaceutical Processing

Factors such as particle size and cleaning ability should be considered when selecting a pharmaceutical filter. Sometimes cleaning is not always a key factor, and the wide availability of single-use options also needs to be considered. For instance, once materials are fed through the top chamber of single-use microcarrier filter bags, gravity forces them through the filter medium.

Bag filters are a good choice for both surface and depth filtration. When chemical compatibility is a concern, propylene bag filters are the choice, while polyester bag filters offer high temperature resistance.

The “cake” approach to pharmaceutical filtration also uses woven fabric as a filter. It depends on the cake that forms on the membrane’s surface to boost effectiveness. This technique is a sort of surface filtration where the medium passes through the cloth and the particles are collected in the holes.

Additionally, for specialized processes or products, the majority of pharmaceutical companies use a variety of pharmaceutical filtration methods. Along with choosing the best options, people need to properly maintain the filters and routinely inspect them for indications of fouling or other unwanted traits.


Each stage of the production of pharmaceuticals is distinct and has particular filtration requirements. The quality standards for filtration products are particularly high because, notwithstanding differences in the process flow, the guarantee needs for product safety are very significant.

Brother Filtration has focused on water treatment and industrial filtration for many years, covering industrial applications in multiple industries, including the pharmaceutical industry and food and beverage industries. It can provide pharmaceutical customers with professional filtration solutions and high-quality products.

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