Downstream Processing

Viral Nanofilter Integrity: Using Variable-Pathlength UV-Vis Spectroscopy for the Gold Nanoparticle Test

Viral filtration (VF) using nanofilters removes endogenous and/or adventitious viruses from biologic drug-substance manufacturing processes (1). The gold particle test (GPT) is performed as part of postuse integrity testing — to complement postuse leakage testing — for cellulose filters such as Planova 20N filters from Asahi Kasei Corporation. First, a proprietary gold-colloid solution matched to the filter type (e.g., 20N) is filtered through the test article. That filter’s pore-size distribution can be assessed using spectrophotometric absorbance readings of the integrity-test…

Adenovirus Downstream Process Intensification: Implementation of a Membrane Adsorber

Historically, companies developing vaccines have used attenuated pathogens, inactivated infectious agents, or antigenic constituents purified from pathogenic sources. In the past 20 years, technological advances such as recombination and viral vectors, have enabled development of vaccines against diseases with previously no available treatments (1). Viral vectors have become one of the most rapidly evolving and promising fields in vaccinology and regenerative medicine. In addition to preventing infectious disease, they have a broad range of potential applications, including treatment of hereditary…

Addressing Regulatory Requirements for Filter Integrity Testing

Filter integrity is a fundamental element of sterility assurance during production of biopharmaceutical and vaccine products. Integrity test results are a key foundation for drug lot release, so any external element that could affect their reliability must be viewed as a critical issue. But when should a filter integrity test be performed? This article highlights the Sartocheck 5 Plus filter integrity tester as a means to address regulatory requirements. Please fill out the form below to read the full article…

Rapid Mammalian Cell Harvest Without Centrifugation for Antibody Purification: Using a Novel System for Cell Culture Media Clarification

Monoclonal antibody (MAb) expression systems typically use signal peptides to ensure secretion of antibodies into cell culture media. Although that reduces the complexity of purification and prevents the need for cell disruption, it does require using expensive and time-consuming techniques to separate cells from antibody-containing cell culture fluids. In this study, we describe our tests of the novel Sartoclear Dynamics Lab V system (Sartorius S Lab Instruments GmbH and Co. KG) for rapid clarification of cell culture media without requiring…

Control of Protein A Column Loading During Continuous Antibody Production: A Technology Overview of Real-Time Titer Measurement Methods

During production of therapeutic antibodies, harvest titer is measured to monitor product mass loaded onto the protein A capture column. This prevents both column underloading (underusing expensive resin) and overloading (wasting product as flow-through (FT)) while allowing for column yield calculations. Batch production yields a single homogenous harvest pool, thus only one titer measurement (along with volume loaded) is sufficient to determine the mass loaded. During continuous production, however, cell-free harvest (permeate) continuously exits a perfusion reactor and loads a…

A Shift of Mindset: How Single-Use Systems Influence Bioprocess Engineering and Project Execution

In past decades, the focus in bioprocess engineering was on traditional stainless steel project management, which is highly dependent on established project schedules. Many milestones, tasks, and deliverables during basic and detailed design and execution were implemented in the same tried and tested way by engineering, suppliers, and biopharmaceutical companies. Making decisions was complicated by alignment with long lead items. With the introduction of single-use (SU) technologies, the transition in execution and optimization of project management only just has been…

An Integrated Bioprocess for Antibodies: From Harvest to Purified Bulk in Six Hours

Antibody production platform processes have been widely adopted in biomanufacturing, but many unit operations are not suitable for integration and automation. Here we describe the work of integrating unit operations by transforming a column operation to a more robust cassette format. We have selected a biomolecule-friendly buffer (phosphate) to eliminate, or delay, the performance of a circulating tangential flow ultrafiltration/diafiltration (UF/DF) operation, so the harvest-to-purified-bulk process can be integrated, resulting in a single, direct-flow operation, that reduces the batch process…

Making Downstream Processing Continuous and Robust: A Virtual Roundtable

Current biomanufacturing is driven to pursue continuous processing for cost reduction and increased productivity, especially for monoclonal antibody (MAb) production and manufacturing. Although many technologies are now available and have been implemented in biodevelopment, implementation for large-scale production is still in its infancy. In a lively roundtable discussion at the BPI West conference in Santa Clara, CA (11 March 2019), participants touched on a number of important issues still to be resolved and technologies that are still in need of…

On Continuous Chromatography: A Conversation with Sanofi’s George Weeden

George S. Weeden, Jr., is a scientist in global manufacturing science and technology (MSAT) process science at Sanofi. We recently chatted about the topic of continuous chromatography. What are the general reasons for companies to consider continuous chromatography? And what are the caveats? The main driver for considering continuous chromatography is reducing the cost of goods (CoG). Continuous chromatography improves productivity (mass of product per volume of stationary phase over time) and thus increases throughput or decreases volumes of stationary…

Modeling Virus Clearance: Use of a Noninfectious Surrogate of Mouse Minute Virus As a Tool for Evaluating an Anion-Exchange Chromatography Method

Viral safety is a critical focus during biopharmaceutical manufacturing (1–5). Although well-characterized mammalian cells such as the Chinese hamster ovary (CHO) line have been used for decades, both endogenous expression of retroviral-like particles and exogenous contamination events from viruses warrant continued vigilance (6, 7). International regulatory agencies require biomanufacturers to validate the “viral clearance” efficacy of their downstream manufacturing process steps before resulting products can be awarded clinical trial or commercial approval (8–10). Currently, viral clearance testing is based on…