An early BPI Lab article addressed the power of liquid chromatographic separations for biopharmaceutical laboratory use (1). Such techniques separate biomolecules based on a number of different properties: size, solubility, hydrophobicity/-philicity, binding affinity. The next most powerful means of separation — and thus high-resolution identification — of nucleic acids and proteins/peptides is based primarily on electrostatic properties: electrophoresis. Although it doesn’t really work in a process or preparative setting, it is a fundamental technique in modern biopharmaceutical laboratories, where it…
Biochemicals/Raw Materials
Accounting for the Donnan Effect in Diafiltration Optimization for High-Concentration UFDF Applications
The biopharmaceutical industry is targeting high-concentration protein formulations to enable subcutaneous administrations. Such administration can provide better patient convenience than intravenous administration. One challenge associated with high-concentration formulations is increased electrostatic interaction between proteins and excipients. That is a result of increased protein-charge density at high protein concentrations. Such interactions can create an offset between excipient levels in final products and diafiltration buffers in ultrafiltration processes. The effect of such electrostatic interactions in a membrane process is known as the…
Impact of Process Interruption on Virus Retention of Small-Virus Filters
Manufacturers of biopharmaceuticals using mammalian cell culture must have processes in place to minimize the likelihood of virus contamination of their products. Regulatory agencies provide guidelines for testing strategies and best practices to assure raw-material safety and control of the manufacturing process. Safety assurance relies on an interdependent matrix of managed risks, including characterization and control of raw materials, extensive testing of process intermediates, and demonstration of the virus removal capabilities of purification unit operations Figure 1: () A dedicated…
Virus Risk Mitigation for Raw Materials
Recombinant protein–based medicinal products and modern cell-based vaccines have a very strong safety history with respect to viral and microbial contamination. However, virus contamination incidents do occur occasionally in manufacturing processes, and they can consume many resources and be expensive to rectify. The root cause of contamination incidents in recent years is most likely the use of contaminated raw materials. These include bovine serum contaminated with reovirus, epizootic hemorrhagic disease virus, Cache valley virus or vesivirus 2117; porcine trypsin contaminated…
Emerging Challenges to Protein A
Protein A affinity chromatography has been a target for replacement since its commercial debut, mainly because of its high acquisition cost. The technique became established despite the cost because it was born into an industrial culture that favored speed to market over manufacturing economy (1). Vendors have since strengthened protein A’s position with incremental but worthy improvements such as higher capacity, lower ligand leaching, and modest tolerance of NaOH. Collateral improvements in polishing technologies, such as the high throughput and…
Enhanced 2-D Electrophoresis and Western Blotting Workflow for Reliable Evaluations of Anti-HCP Antibodies
Biologic drugs are subject to unique regulatory and technical requirements because of their origin and expression in genetically engineered host cells, as well as their underlying physicochemical properties and elaborate purification processes. One such requirement is the accurate monitoring and effective removal of process-derived impurities such as host-cell proteins (HCPs) and DNA/RNA, viruses, cell culture media, chromatographic leachates, and so on (1). Of those impurities, HCPs are perhaps the most challenging to accurately monitor. Each expression system’s proteome consists of…
Upstream Chemistry Analysis in Cell-Based Process Development
Cell line selection is important to any pharmaceutical company’s development pathway for biological compounds (1). In cell-line selection laboratories, many different, slightly variable cell lines are tested in parallel for desired characteristics. Candidate cell lines are chosen for further development on the basis of their performance in basic tests of critical quality attributes (CQAs). Historically, such cell lines were selected in large-volume containers because it was necessary to have sufficient volume in culture to allow repeated sampling without damaging the…
Standards for Ancillary Materials Used in Cell- and Tissue-Based Therapies
Cell- and tissue-based therapies are being used increasingly to treat many diseases for which currently no other adequate treatment options are available. These products contain human or animal cells that can replace, regenerate, or augment a recipient’s diseased, dysfunctional, or injured cells, tissues, or organs. Cells or tissues might be unmanipulated, or their biological characteristics can be altered ex vivo before administration of the final product to patients. Examples of cell therapies range from traditional blood transfusions to recent approaches…
Protein A
The number of blockbuster monoclonal antibody (MAb) drugs continues to grow. In 2008, MAbs generated revenues in excess of US$15 billion (1), making them the highest-earning category of all biotherapeutics. The world MAb market will reach $62.3 billion in 2015, with next-generation therapeutic antibody revenues reaching $2.3 billion in 2015 according to Visiongain reports published in September and November 2011 (2, 3). Biosimilar antibodies will also begin to enter established markets as regulatory authorities clear approval pathways for them. Most…
A Salt-Tolerant Anion-Exchange Chromatography Sorbent for Flexible Process Development
In most downstream purification processes designed for biopharmaceutical drug production, dilution and diafiltration sequences are unavoidable. Such operations are routinely used to adjust a feedstock or chromatographic fraction to the optimal conditions required for best process performances. Nevertheless, those steps are often time, water, and labor consuming without participating directly in final product purification. Because biopharmaceutical production is increasingly driven by cost reduction, a possible means for enhancing process economics is to streamline purification by eliminating these unit operations before…