Pall Corp.: Allegro Single-Use Tangential Flow Filtration System

The Allegro single-use TFF system is designed specifically for the incorporation of single-use components. It is not a disposable version of a traditional TFF system design because new concepts for ease-of-use in single-use processing have been used to achieve this unique design. This includes careful consideration of the layout and installation, allowing full access to components from one side of the system.Single use technology is widely accepted in bioprocessing, with key benefits being the elimination of cross contamination and cleaning, and greater system flexibility.Tangential Flow Filtration (TFF) is more complex than many other unit operations for which single-use approaches have been adopted. In TFF, cleaning of the TFF casettes and system is essential to maintain flux and minimize the risk of cross contamination in a multi-product facility.The Allegro system provides a platform onto which five single-use manifolds are attached. The five manifolds – feed, retentate, permeate, retentate biocontainer and recovery – are provided gamma irradiated and ready to install on the system.The single-use flowpaths have incorporated single-use sensors where possible. These sensors are manufactured to defined tolerances and minimize downtime in system set up.Integration of sensors in this system:

•  Allows tracking of key process parameters
• Provides notification when processing is not within specification
• Enables automated control of processing to optimum conditions
• Facilitates fully automated process sequences

Components in the single-use flowpaths have been selected to achieve the performance requirements of the system. Use of components and materials which:

• Meet the flow and pressure requirements of typical TFF processes
• Achieve scalability of performance
• Have full specification and certification
• Have easy attachment and connectivity

System Description

The Allegro single-use TFF system has been designed for ultrafiltration and diafiltration (UF/DF) processes. Typical applications are concentration and diafiltration of proteins, recombinant molecules, potent biological and cytotoxic drugs, and vaccines.

It is fully automated, with a disposable flow path comprising high quality components in five easy to install manifold sets. The 1⁄2 in. ID (internal diameter) system has a recirculation pump capacity of 1000 L/hour, and can typically run 0.5 - 2.5 m2 cassettes (running at a crossflow of 5 L/min/m2). It can be fitted with a 20 L or 100 L retentate biocontainer, and operated in fed batch mode. Cassettes are placed between single-use distribution plates, which are components of the feed and retentate flow paths. The cassette assembly is torqued between two stainless steel plates (non wetted parts), to ensure correct sealing.

Connections can easily be made to Allegro 2D and 3D biocontainers for supply of WFI, diafiltration buffer and process fluid in fed batch operations. Product temperature control, either cooling or heating, is available using a heat exchange plate under the retentate biocontainer.

Features

• Pressure independent flow provided by a positive displacement diaphragm pump ensures that critical parameters do not vary during the concentration step
• Fully automated system for control and monitoring of key process parameters
• Good accessibility for installing flowpaths and daily operation
• Pre-irradiated manifold sets for feed/retentate/permeate/fed batch/recovery
• Installation of manifold sets typically takes around 20 minutes