Silicone rubber is widely used in the pharmaceutical industry, where sterilizability is an essential requirement for all fluid transfer equipment. Pharmaceutical products are sterilized frequently and repeatedly by high-level energy and/or chemical vapor to eliminate bacterial surface contamination. Such treatments may also affect the molecular structure of silicone rubbers, causing changes in their physical properties and performance. Several studies on this topic have been reported; until now, however, no systematic investigation has been performed on the effect of…
MAb
Improved HCP Quantitation By Minimizing Antibody Cross-Reactivity to Target Proteins
Host cell proteins (HCPs) are process-related impurities derived from a host cell expression system that may be present in trace amounts in a final drug substance. During biologics development, it is important to demonstrate that a bioprocess is efficient in removing HCPs and that it provides consistent control of HCP levels. Several techniques are typically used for detection, quantitation, and risk evaluation of HCPs in biologics. The most common are enzyme-linked immunosorbent assays (ELISAs), Western blotting, sodium-dodecyl-sulfate polyacrylamide…
Nutrient Supplementation Strategies for Biopharmaceutical Production, Part 3
Scale-up studies are needed for assessing cell culture production system options and for testing nutrient supplementation techniques as well. With the many supplementation options available, choices need to be made as early in product development as possible because advantages can change with scale. One published fed-batch scale-up study testing from 3 L up to 2,500 L highlights items to be considered in addition to the nutrient supplementation process such as the impact of pH and CO2 control (1).…
Primary Clarification of Very High-Density Cell Culture Harvests By Enhanced Cell Settling
In recent years biopharmaceutical manufacturing has demonstrated major improvements in MAb production, exhibiting product titers as high as 25 g/L often associated with very high cell densities (1). High-density cell cultures with >150 million cells/mL pose a great challenge in clarification and further downstream processing because of a need to remove a large amount of biomass and increased levels of contaminants from cell debris generated during cell culture and harvesting. Production of biological substances (MAbs, in particular) usually…
Efficient Development of Stable High-Titer Cell Lines for Biopharmaceutical Manufacturing
Commercial manufacturing of therapeutic monoclonal antibodies (MAbs) commonly uses mammalian cells to generate large quantities of a drug. Identifying cell lines that stably produce high protein titers is, therefore, a critical part of biopharmaceutical development. Unfortunately, identifying suitable cell lines is traditionally a time-consuming, labor-intensive process. That’s because their productivity and stability can vary enormously, so large numbers of clones must be screened to find those with both the highest yield and a desired level of product quality (1). Cell-line…
Rapid Assessment of Vaccine Potency
The global vaccine market is growing annually by 16% and is expected to reach $21 billion by 2010 (1). Much of the predicted growth of this market is expected to come from the introduction of new vaccines, either against diseases for which no vaccine currently exists or as second-generation products to replace existing ones. Much research is still centered on developing vaccines to prevent infectious diseases caused by microbial and viral pathogens. This segment is being fueled by a number…
Setting the Stage
Much has already been written lately about addressing the so-called “downstream bottleneck(s).” A number of companies are leading the way toward developing products and platforms for reducing both the costs and the time required for downstream processing. Our task with this special issue was to provide a state-of-the-art update on these activities — but as always, within a limited number of pages allotted. The primary issue behind this bottleneck debacle is to address purification challenges posed by aggregation in cell…
Development of a High-Capacity MAb Capture Step Based on Cation-Exchange Chromatography
Protein A affinity chromatography is traditionally used as the capture step for monoclonal antibodies (MAbs) (1,2,3). It yields high purity because only the fragment-crystallizable (Fc) region of an antibody (IgG1 or IgG2) or Fc-containing fusion protein can bind to the protein A ligand. The resulting specificity provides substantial reduction in impurities such as host cell proteins (HCPs) and DNA (4,5,6,7,8). The dynamic binding capacity of protein A chromatography resins is generally ≤40 g/L and depends highly on residence time because…
Production of Recombinant Whole-Cell Vaccines with Disposable Manufacturing Systems
Live whole-cell bacterial products have been used as vaccines for many years, and there are currently three such products licensed on the market. Over recent years, however, interest has renewed in this type of product as a delivery system for novel recombinant therapies and vaccines. A number of different organisms have been proposed, such as Escherichia coli and Salmonella species, which might have applicability for such applications. Vaccine applications tend to relate to the potential for low-cost orally delivered products…
Novel Vaccines and Virology
Vaccines have been around a long time — longer than any other biologic medical products. Since the 1700s, when a British doctor inoculated people against smallpox using Variolae vaccinae (cowpox virus), we’ve referred to such immunizing treatments as “vaccines.” Most children in developed countries grow up knowing there will be occasional “vaccinations,” usually injections, required to get into school and stay there (which may or may not seem like a great thing, depending on who you talk to). Similarly, people…