Understanding Clarification and Prefiltration in Pharmaceutical Production

Prefiltration’s primary goal is to protect and extend the life of more expensive and critical downstream final/sterilizing filters. The prefilter removes larger contaminants that reduce the chances of prematurely clogging of final/sterilizing filters. Prefilters are typically less expensive and allow the final/sterilizing filters to last longer, ultimately reducing overall costs. Different types of prefilters are used within the pharmaceutical process depending on the filtration goal.

Types of Pharmaceutical Prefilters

Particulate Prefilter – removes larger particles and contaminants typically present in feedstock streams and early in the process. Micron ratings are typically 5 or greater.

Clarification Prefilter – removes visual impurities/contaminants that can affect product quality while protecting downstream filtration. Micron ratings are typically around 1 micron or less.

Sterilizing Prefilter – one of the more critical prefiltration steps, removes a majority of sub-micronic contaminants/microorganisms that could clog the final sterilizing filter. Mircron ratings are typically around 0.65-0.2 microns.

Importance of Pharmaceutical Prefilters

Prefilters are vital in pharmaceutical production as they are the workhorses that remove the majority of contaminants and microorganisms from the process. A filtration audit of your system can help to identify process improvements that could significantly lower the overall cost of filtration. Contact our experts here if you are interested in reducing your cost of filtration.

Particle and Clarifying Prefiltration Recommendations

Prefiltration goals and requirements greatly differ in each pharmaceutical process. Some are as simple as removing 5-micron particles with one filter. Others may require particles from 100-1 microns to be removed and require multiple steps and thus, multiple filters. Another consideration is prefiltration layers, which could combine prefiltration & final filtration into one step.

Single Step Prefiltration

If your goal is to remove particles at a specific micron rating and above, you can typically use a properly rated depth or pleated depth filter. For larger particles and high particle concentrations, a meltblown depth filter could be used. For smaller particles with high-moderate particle concentrations, a pleated depth filter is typically used. The choice should also be determined by filter life, target flow rate, and material compatibility.

Multi-Step Prefiltration

If your goal is to remove a wide range of particles at differing micron ratings, you will typically need a “filter train” or multiple filtration steps. This is because if you only have a single filter it can clog too quickly due to high load across a wide particulate range. Understanding the particle size distribution is key to maximizing the effectiveness of a filter train. A distribution range will show you where you can most effectively reduce the particulate load for each filtration stage. The goal is to maximize filter life while minimizing operating costs. The Global Filter team can assist in determining the optimal filter train for your process.

Choosing the Right Prefiltration in the Pharmaceutical Industry

There are plenty of opportunities for optimization in your clarification and prefiltration steps in your pharmaceutical process. Optimization can lead to extended filter life, longer processing times, and less load on final filtration. The Global Filter team can assist in optimizing your prefiltration needs, and help you with the necessary testing to help optimize your process. Our wide range of filtration products allows us to provide you with a variety of options to optimize your process and reduce operating costs. For more information, contact our sales team here.

Recommended Pharmaceutical Prefiltration

Global Filter suggests a few prefiltration options for these applications: