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Membrane Filtration Technology in Plasma Exchange*
Published in James L. MacPherson, Duke O. Kasprisin, Therapeutic Hemapheresis, 2019
Robert R. Stromberg, R. Alan Hardwick, Leonard I. Friedman
In plasma exchange, the process is called “cross-flow” filtration, which differs significantly from “dead-end” filtration. As shown in Figure 1, in cross-flow filtration the blood passes parallel to the surface of the membrane, while the substances to be removed from the blood pass perpendicularly through the membrane into the filtrate compartment. Filtration efficiency is governed by many parameters. These include: blood flow rate, pressure difference across the membrane, geometry of the blood flow path, composition and physical structure of the membrane, and the physicochemical nature of the substances that pass through the membrane. In addition to these parameters, consideration must be given to module biocompatibility, sterilizability, and cost. Filtration module operating conditions must be such that cellular and noncellular damage to the blood is avoided.
Biologic Drug Substance and Drug Product Manufacture
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Ajit S. Narang, Mary E. Krause, Shelly Pizarro, Joon Chong Yee
In this step, the cell culture harvest, consisting of target protein in the dissolved state and suspended solids such as cells and cell debris, is subjected to sedimentation, centrifugation, deep bed or depth filtration, and one or more steps of microfiltration. Sedimentation and centrifugation: Gravitational and centrifugal rotational settling of particulate matter allows initial separation of most of the particles from the fluid for initial clarification.Depth filtration or deep bed filtration consists of a porous filtration medium that retains particles throughout the medium, rather than just on the surface. This process is particularly suitable for fluids with high particle load since the filter can retain a large mass of particles before getting clogged. Depth filters provide high surface area and adsorptive surface. In addition to adsorbing impurities from cell culture supernatants, depth filters can also remove viruses (Yigzaw et al. 2006).Microfiltration involves passing the fluid through a specific pore size membrane to effect removal of microorganisms and suspended particles. Suspended particles are retained (“retentate”) on the feed side of the membrane, while the dissolved liquids, including the protein of interest, passes through (“permeate”). A cross-flow filtration process, where the fluid is moved in a direction tangential to the membrane surface, is preferred compared to the dead-end filtration (where the fluid is forced through the membrane surface at a dead end to the direction of flow).
Advances in influenza virus-like particles bioprocesses
Published in Expert Review of Vaccines, 2019
Laurent Durous, Manuel Rosa-Calatrava, Emma Petiot
Membrane-based processes of clarification emerged as a reliable alternative to centrifugation methods, especially for large production volume. Indeed, they present increased scalability and better control of the shear stress applied to the product [84]. Normal-flow filtration (NFF, or dead-end filtration) and tangential-flow filtration (TFF, or cross-flow filtration) with micrometer scale cutoff filters are used. Depending on the filter’s material and their dimensional arrangement, depth filters can advantageously partially absorb HCP and DNA [12,84]. Thus, several academic and industrial studies applied membrane-based processes for clarification. 0.2 µm NFF sterile microfiltration was sued for bulk clarification of influenza-VLP bioreactor batches [30,43,64] and Redbiotec implemented disposable depth filters thus reaching 90% recovery of HA antigens [58] (Table 2).
Merits and advances of microfluidics in the pharmaceutical field: design technologies and future prospects
Published in Drug Delivery, 2022
Amr Maged, Reda Abdelbaset, Azza A. Mahmoud, Nermeen A. Elkasabgy
Tangential flow filtration was used to purify and concentrate solid lipid nanoparticles after microfluidizer homogenization (Anderluzzi et al., 2019). This method involves the recirculation of the sample to be purified across ultrafiltration polymeric membranes for solvent exchange using a pressure-driven purification process. Unlike the conventional dialysis method (dead-end filtration method), membrane fouling is minimized, and a high filtration rate with higher product recovery is maintained. Tangential flow filtration devices can process sample volumes as small as ten milliliters or as large as thousands of liters, potentiating their use in nanoparticles purifications on large scales (Interchim Innovations, 2021; Pall Corporation, 2021).