Perfusion systems for animal cell cultures are increasingly used for high cell density processes to enhance the productivity of bioreactors. There are four different process modes that can be used in animal cell cultivation: batch, fed batch, continuous culture, and perfusion culture. In both batch and fed batch, the metabolite concentrations cannot be kept constant and the accumulation of catabolites like lactate and ammonium limits the process duration to about ten to 15 days. In contrast, with continuous and perfusion processes, there is a constant influx of fresh cultivation medium and a corresponding removal of recombinant protein and catabolites. The concentrations of metabolites remain relatively constant and the process duration is not limited by the buildup of waste products. This extends the duration of these cultures to several weeks or months. The resulting steady-state conditions for metabolites can enhance cell-specific productivity and product quality, for example, by improved glycosylation or reduced aggregate formation. In continuous culture, cells are removed in the effluent and this limits the product output per liter of bioreactor volume (volumetric productivity). In contrast, substantially higher cell concentrations are attained in a perfusion system because the cells are retained in the bioreactor resulting in increased volumetric productivity. A five- to 20-fold improvement over batch cultivation has been reported for perfusion cultures…
Tag: <span>biopharmaceutical manufacturing</span>
Continuous cell lines of Drosophila have now been in use for more than two decades as hosts for the expression of heterologous gene products. The most popular are the Schneider lines 2 and 3 (S2, S3) and a few derivatives of the Kc line. These have been widely employed for both stable and transient gene expression. The S2, in particular, is an exceptionally versatile system that has proven to be useful for high-level protein production. S2 cells have been used for the expression and analysis of intracellular, secreted, and membrane-associated proteins. This includes cytokines, antibodies, receptors, and viral antigens. These have all been shown to be authentically-processed, biologically active, and produced to high levels. The cell line is ideally suited for the development and industrial-scale manufacturing of a wide range of biopharmaceuticals including vaccines and therapeutic protein products. Compared to conventional technologies, the strengths of the S2 expression technology lie in its quick access to proteins, excellent protein expression capability, scalability, regulatory-friendliness, and applicability to high cell density perfusion cultivation…
Single-use systems (SUS) have been employed in biopharmaceutical manufacturing for over 15 years. Consistent year-to-year growth has been seen both in the total volume of sales and the number of manufacturing steps in which SUS are being used. It is projected that the majority of commercial-scale biologics manufacturing will be done in disposable equipment in the near future because of improvements in SUS design and innovation. These devices can significantly reduce capital costs (for example, stainless steel vessels), eliminate equipment cleaning and sterilization, improve turnaround times, and reduce concerns about microbial contamination within a production facility. As reported in this year’s 8th Annual Survey of Biopharmaceutical Manufacturing, however, the rate of growth in SUS use may be slowing. Contributing factors are: 1) the economy; and 2) the need for more consistent product standardization (e.g., design, quality, and leachables/extractables [L&E]) data that regulators and industry end-users can accept with confidence…
While global economies continue to struggle back from the recent recession, we are seeing clear evidence that budgets in most areas of biopharmaceutical manufacturing are returning to pre-crisis conditions. Because of the essential nature of pharmaceutical products and health services, healthcare sectors tend to be more recession resistant and return to growth sooner than other industries. In fact, respondents to our 8th Annual Report and Survey of Biopharmaceutical Manufacturing projected only increases for all budget areas this year. This is a change from last year where budgets continued to show decreases in areas ranging from outsourcing production, hiring new scientific staff, and new facility construction. As the financing crunch lightens, biomanufacturing facilities are reopening their wallets. However, anecdotally, vendors to the industry are indicating that buyers are continuing to be much more cautious with their spending. Sales cycles continue to be drawn out, and many end users are demanding more milestone performance and risk sharing from suppliers…
This paper places the “Quality by Design” (QbD) in an overall context and provides the following straightforward definition so that QbD can be effectively used to solve a wide variety of important problems:
Quality by Design–During the design stage, to achieve a well-defined goal, iteratively apply science and engineering methods to anticipate, identify, understand, resolve, and control problems that will be encountered during testing, operating, and verifying the goal over its lifecycle.
The viewpoint of the paper is to view QbD as “Success by Design.” The definition is based on answering the following question: What will be required to provide assurance that the enabler developed during the design stage will successfully reach the goal over the entire lifecycle before leaving the design stage? The paper argues that QbD should not be implemented as a program, but used as a tool. To provide understanding, the paper explores underlying concepts, the history of QbD, develops a working definition, and then applies it to biopharmaceutical development and manufacturing…
Tangential flow filtration (TFF) microfiltration has been used as one of the choices for clarification of mammalian cell or microbial cell culture in the biopharmaceutical industry. Unlike the ultrafiltration process for protein concentration and the diafiltration application where the feed solution is relatively clean (free of colloids or larger particles after the clarification/purification process), the microfiltration process needs to handle a rather high-fouling feed stream such as cells, cell debris, colloids, etc. In a previously published article, we discussed that a TFF microfiltration step is limited by a maximum throughput or capacity obtainable under a given set of operating conditions. Some distinct microfiltration characteristics, such as critical permeate flux, permeate flux control, and maximum throughput were explained in that article…
This article reports the average titers and yields currently attained with commercially manufactured biopharmaceuticals expressed by microbial systems such as E. coli and yeasts. A recent BioProcessing Journal article comparably covered results from the first phase of this study concerning historical titers and yields attained for commercial-scale biopharmaceutical production using mammalian cells (e.g., CHO). As with this prior mammalian component, public domain data concerning titers and yields attained with microbially manufactured products were obtained using all available sources.