Peristaltic pumps, comprised of a drive, pump head, and tubing, offer several advantages that make them a popular choice for aseptic filling. Key features include fluid isolation within the tubing, quick tubing replacement, reversible flow, dry running capabilities, and low maintenance costs.
In aseptic filling, common metering methods include time-pressure, plunger pump, and peristaltic pump. However, with the rise of biopharmaceuticals and advancements in single-use technologies, peristaltic pumps are increasingly used for large-scale production. Compared to plunger pumps, peristaltic pumps offer distinct advantages:
· Functional Considerations: Peristaltic pumps can accommodate a wide filling volume range (0.1ml to 500ml), depending on the tubing diameter. Changing the filling volume simply requires replacing the tubing, eliminating the need to purchase and store different pump bodies.
· Aseptic Considerations: Plunger pumps consist of multiple mechanical components that come into contact with the product, such as seals, plungers, pump bodies, and valves (if required). These components must be assembled, cleaned, and sterilized before use. In contrast, peristaltic pumps can be used with single-use disposable components (buffer bags, tubing, filling needles), eliminating the need for pre-use cleaning and sterilization and preventing cross-contamination from the filling circuit. Even with SIP/CIP capabilities, plunger pumps incur significant time and energy costs.
· Product Suitability Considerations:
o Plunger pumps have a gap between the piston and pump body. When high-flow rate fluids pass through small-diameter passages due to piston compression, the resulting shear force may adversely affect shear-sensitive biological products.
o For high-viscosity products, piston compression can create significant internal pressure, affecting filling accuracy, especially in micro-filling applications. Peristaltic pumps, on the other hand, generate relatively low filling pressures.
o For products that react with metal components, single-use, metal-free filling assemblies prevent product-metal contact.
The tubing used in peristaltic pumps significantly impacts overall performance. Factors such as uniform wall thickness, fatigue resistance, and material "memory" should be carefully considered when selecting tubing.