Proper filtration is an essential requirement in pharmaceutical manufacturing. In fact, it’s required at multiple points in those processes. As a result, there are various filters that are need in pharmaceutical processing, including magnetic filters, bag filters, and self-cleaning filters, which are used in liquid filtration systems such as surface filtration, depth filtration, and ultrafiltration systems.
Why Filters Are Needed in Pharmaceuticals
Filtration and separation processes are not just important in the pharmaceutical industry, they are absolutely critical. Proper filtration makes sure that the products manufactured are safe for patients and ensures that manufacturers are not losing valuable products due to improperly working filtration processes.
Product safety is paramount in pharmaceutical production, which means that the highest quality standards have to be maintained. As a result, the filtration systems and filters that are used have to be effective in the filtration of aggressive fluids at multiple points in the process.
Filtration Systems Used in the Pharmaceutical Industry
In the pharmaceutical industry, there are different types of filtration systems that are frequently used. These systems include surface filtration, depth filtration, and ultrafiltration. Each system has unique uses and advantages.
Surface Filtration – Surface filtration systems are used to retain particles on the surface of the liquid that is being filtered. As the particles build up during the filtration process, a layer of material forms on the surface. This layer is important as it increases the efficiency of the filtration process. In fact, once the layer of material is formed, it can increase the rate of filtration from about 55% up to 100%. Of course, over time, the layer will cause a reduction in the flow of liquid, so it must be maintained regularly.
Depth Filtration – Depth filtration involves liquid flowing down a long pathway, passing through various filter layers along the way. In this process, particles, soluble materials, and colloidal materials are removed from liquid. The process begins with filters that reduce larger particles, and then along the pathway, progressively smaller and smaller impurities are filtered out. While depth filtration systems are more costly than surface filtration systems, they typically last longer and filter smaller particles.
Ultrafiltration – Ultrafiltration systems are used to remove the smallest particles (0.01 micron) from liquid, as well as contaminants like viruses, bacteria, protozoa, and other hazardous microorganisms.
Filter Types for Pharmaceutical Processing
In addition to the different filtration systems that are used, there are various types of filters important to the pharmaceutical industry. These filters include magnetic filters, bag filters, and self-cleaning filters.
Magnetic Filters – Magnetic filters are commonly used in liquid pharmaceutical production to remove iron particles from the fluids. These filters are typically able to be cleaned and reused when they become full. Magnetic filtration’s other advantages include minimal running and disposal costs and being environmentally-friendly.
Bag Filters – Bag filters (such as these) are a cost-effective option for use in pharmaceutical processes. These filters use microfiltration to remove contaminants from liquids. Bag filters, named as such because the debris that is filtered out is collected in a bag, come in various pore sizes to meet the varying filtration needs of pharmaceutical production processes.
Self-Cleaning Filters – Self-cleaning filters are ideal for high-demand, large scale filtration systems. The biggest benefit of these filters is that they perform their own maintenance. With other types of filters, the filtration system has to be completely stopped for maintenance to be performed. Self-cleaning filters don’t require that as they use backwashing to push debris away from the sides of the filter and towards the bottom of the filter’s housing. From there, the debris are pushed all the way out of the system, while the filter stays in place.
Where to Use Liquid Filtration in the Pharmaceutical Process
Liquid filtration and separation are requirements of multiple processes within pharmaceutical production. Some of the applications where liquid filtration is used include:
- Clarification and prefiltration for the removal of solid impurities, undissolved powders, and particles to ensure a high-quality end product and to protect equipment further downstream
- Solvent filtration in the production of Active Pharmaceutical Ingredients (APIs)
- Formulation and powder blending of the various combined substances, including the active drug, to produce the final medical compound
- Bioburden reduction for the reduction in particles or bacteria reaching the final sterilizing filtration stage
- Sterile filtration of the final product
- Sterile water-for-injection for diluting and dissolving drugs
This is certainly not an exhaustive list as there are many processes in pharmaceutical manufacturing that require the careful and thorough filtration of liquids. Because of this, it’s important to understand the types of filtration systems and filters that are commonly used in the industry.
Selecting the Right Filter for Pharmaceutical Processing
Pharmaceutical processing facilities are all different, with unique filtration needs. Because processes vary and product safety is so important, it’s crucial that manufacturers consult with a reputable filtration company to make sure that they are receiving the right filters for their particular need.