Filtration

Using 3D Imaging To Understand Sterilizing-Grade Filtration of Liposomes

Sterilizing-grade filtration is an essential operation for biomanufacturing. It ensures that drug substances are free from microorganisms at the end of a downstream process. The COVID-19 pandemic has highlighted the need for high-quality therapies to be manufactured efficiently at scale, with particular focus on the need for multiple vaccines to be developed, produced, and distributed globally (1). Some vaccines have used lipid nanoparticle encapsulation technology, which also has potential for use in gene therapy development in the near future. Lipid…

The Impact of Protein Stability on Virus Filtration

Filtration of protein-based biologics is essential for minimizing viral contamination and ensuring product safety and high quality. The tendency of therapeutic monoclonal antibodies (MAbs) and recombinant proteins to aggregate under a number of conditions can complicate selection of a virus filter. An increasing demand for high concentration formulations creates additional challenges. When performing filterability studies and to ensure meaningful virus filter evaluations, downstream process scientists must address factors that can lead to aggregation. This special report on virus filtration by…

Reducing Downstream Scale-Up Needs: Advances Toward Continuous Downstream Processing

The biopharmaceutical industry generally acknowledges that upstream and downstream aspects of drug-substance manufacturing are experiencing a capacity mismatch. Today, many recombinant proteins can be produced at expression titers of 3 g/L, with some yields exceeding 10 g/L. Such titers represent 100-fold increases in production capability compared with values from twenty years ago (1, 2). Increases in cell-culture density and improvements to perfusion-mode bioreactor systems hold promise for increasing yields further still. Such developments, combined with the broad availability of concentrated…

Comparing Single-Use Multicycle Cake Filtration with Depth Filtration: Eliminating the Downstream Bottleneck

Over the past few decades, single-use (SU) technology has increased bioproduction efficiency significantly, especially with the introduction of disposable bioreactors in upstream processing. To keep pace with major developments and increases in upstream capacity, downstream processes also must increase capacity and efficiency. However, cell harvesting and downstream processing continue to present bottlenecks in manufacturing (1). Typical clarification processes are composed of primary and secondary clarification steps, such as centrifugation followed by depth filtration, respectively (1). Two sets of SU depth…

The Effect of Benzonase Endonuclease Addition to Purification of Sabin Poliovirus Type 3

During production of vaccines and viral vectors, the size and quantity of extracellular nucleic acids must be reduced using endonuclease enzymes. Merck/MilliporeSigma’s proprietary Benzonase endonuclease is a genetically engineered nuclease derived from the Gram-negative bacteria Serratia marcescens. It attacks and degrades all forms of DNA and RNA. It is manufactured under good manufacturing practice (GMP) conditions and has a drug master file (MDF) in place with the US Food and Drug Administration (FDA), which can be cited in regulatory filings.…

Validation of a Next-Generation Single-Use Turbidity System

Turbidity describes the relative clarity of a liquid as the result of suspended solids. Instruments that measure turbidity typically use a beam of light to detect particles by measuring the difference between the amount of light emitted from the light source and the amount that is received by a detector. Such measurements are affected by the size, shape, and number of particles in a sample of liquid because those solids scatter the incoming light, which provides an apparent absorbance that…

Drug Formulations Are Changing:
New Sterile Filtration Challenges in the Changing Landscape of Drug Formulations

Read about the challenges of sterile filtration of high concentration mAbs, liposomes, and lentiviral vectors, and how to solve them in this Special Report. Development of new, complex drug formulations has given us therapeutics with properties that are markedly different from traditional drug types. High viscosity or low surface tension formulations or large viral vector molecules can mean that sterile filtration processes, which are optimized for traditional drug types, are not as efficient for the new, complex formulations. Premature filter…

Development of a Single-Use Hermetic Centrifuge System for Mammalian Harvest with Moderate to High Cell Content

The production of increasingly higher cell densities has stressed the already limited solids-handling capabilities for traditional intermittent ejection centrifuge systems. By contrast, a single-use disc-stack centrifuge based on the solids-flow principle offers distinct advantages for cell culture harvesting. Such benefits include solids handling of high-density cell culture processes and elimination of the separation disruption and aerosol generation associated with the intermittent solids ejection. A single-use system also provides well-established benefits of disposable components — such as removal of steam- and…

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…

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…