Redesigned Filter Capsule Improves Final Filtration Assembly Design And Operation

Single-use components are increasingly being implemented in the manufacture of medicinal products. They offer manufacturers increased flexibility and the opportunity for improved efficiency as they strive to meet the demands of today's production schedules. In final filtration and filling operations, where maintaining sterility is critical to assuring drug safety for patients, sterilized single-use assemblies offer many advantages.

As manufacturing processes have evolved, so has the design of our filter capsules. On Millipak® Final Fill capsule filters, the traditional filter vent has been replaced with a specialized port that has been validated to prevent microorganisms from the outside environment from entering the aseptic flow path. This port can be used for venting, sampling and for connecting an air-line, thus simplifying pre-use, post sterilization, integrity testing (PUPSIT). In contrast to traditional filter vents, the aseptic multi-purpose port (AMPP) is designed to maintain an aseptic connection while tolerating the high pressures required for filter integrity testing. In addition, following processing, pressure can be applied through the AMPP to recover product in the filtration system. In small volume processing or where high value drug products are being processed, this recovery step can have significant economic benefits¹.

In addition to the operational benefits, aseptic connections through the AMPP, rather than the filter inlet, offer opportunities for streamlined single-use assembly designs. In single-use redundant filtration (SURF) assemblies, where two sterilizing-grade filters are directly connected in series, the potential benefits of streamlined connections for both reducing hold-up volume and minimizing contamination risks are clear².

This application note describes testing performed to assess volume loss in SURF assemblies and shows how both assembly design and filtration operations can be adapted to minimize volume and product loss in the system.