Downstream processing of biopharmaceuticals is costly and time-consuming, often involving multiple steps with significant time and energy expended on maximizing product quality and yield. Affinity chromatography is one of the simplest and most effective methods for purifying protein and peptide therapeutics, offering reduced process steps and therefore higher yields than nonaffinity methods can provide. Protein A is widely used for affinity purification of monoclonal antibodies (MAbs), Fc fragments, and Fc fusion proteins. But it is a challenge to…
Downstream Processing
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…
PAT-Based In-Line Buffer Dilution
Technological advancement has taken protein expression titers from concentrations measured in mg/L to those measured in g/L over just a few years (1). Annual demand for antibodies has reached several metric tons, which has spurred production of >100 kg batches of protein at a time (2). As upstream yields continue to increase, downstream purification involving process solution preparation and delivery must increase in proportion to keep pace with demand. That has placed facility and instrumentation capacity constraints front…
Questioning the Downstream Bottleneck
In preparing for our October supplement on bioprocess design, BPI’s contributing editor Lorna D. McLeod spoke with Bayer Healthcare’s Harald Dinter (vice president of global biological development) and Jens Vogel (CMC development team leader and head of isolation and purification in global biological development) about the downstream bottleneck. Is it or isn’t it a real problem? Does the answer depend on your point of view? BPI: “Does a company’s downstream capacity place practical constraints on increasing production titers? Is that…
50 Years of Sephadex Media
It has been 50 years since the first Sephadex paper was published (1). Readers of BioProcess International work in a field that was fundamentally affected by what happened after that paper appeared in 1959. So this anniversary is certainly worthy of a party and a few speeches. But there are lessons to be learned, too. Here we take a look at threads connecting events before and after the discovery of gel filtration chromatography and introduction of the Sephadex product. Interdisciplinary…
Investigating Flow Distribution and Its Effects on Scale-Up
Depth filtration is widely used in the biopharmaceutical industry to purify target proteins by removing whole cells, cellular debris, fines, aggregates, and colloidal particles from the fermentation broth (1,2). At large scale (>2,000 L), culture harvest from a bioreactor is typically processed with a disc-stack centrifuge to remove cells and cell debris. Although centrifugation is very effective for removing whole cells and larger debris, it cannot remove small-size particles, which remain suspended in the centrate. Depth filters are commonly used…
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…
The Road to a Fully Disposable Protein Purification Process
What’s keeping senior biopharmaceutical executives awake late at night? According to BioPlan Associates, Inc., which publishes an annual comprehensive survey of the state of worldwide biopharmaceutical manufacturing, capacity constraints are among the key issues at hand (1). And one of the most important constraints is the lack of physical capacity in purification equipment. Bioreactors are producing a lot more protein than current downstream purification steps are designed for. Overcoming the resulting bottlenecks may require increasing the productivity of…
Single-Use Strategies in Bioprocessing
BioProcess International has followed, from the beginning, the ways in which single-use technologies have transformed the landscape of industrial bioprocessing. On 18 March 2009, we organized a panel session at the annual Interphex conference (Jacob Javitz Center, NYC) to drive discussion toward longer-term implications of single-use components and technologies on the future of bioprocessing. Is their use a cost-saving strategy overall? What economic factors are driving their adoption? The panelists were prepared to address such topics as economic considerations in…
Single-Use, Continuous-Countercurrent, Multicolumn Chromatography
Manufacturing processes for biopharmaceuticals have undergone significant changes over the past decade. One of the most striking results of improved process sciences is the dramatic rise in expression levels from animal cell cultures. Figure 1 shows how some monoclonal antibody titers have increased about 30-fold over the past 15 years. These increasing titers have allowed current biomanufacturing facilities to produce larger product quantities than anticipated at the time they were designed and built. Figure 1: As a…