Analytical

A Practical Method for Resolving the Nucleation Problem in Lyophilization

Given the prevalence of lyophilization and the growing pipeline of sensitive biological drugs requiring stabilization, pharmaceutical development and manufacturing personnel need complete, reproducible control over the operation, scale-up, and transfer of their lyophilization processes. To address the nucleation problem, Praxair has developed a step-change technology that adds consistent control to the freezing step of lyophilization. This low-capital, plug-and-play option can be readily implemented on most existing freeze-dryers with minor equipment additions and controls integration. Adoption of the technology requires no…

Interest in Hollow-Fiber Perfusion Bioreactors Is Growing

People who regularly culture animal cells become so comfortable with standard techniques that novel approaches can seem contrived or even unnatural. However, the typical cycle of seeding cells at very low density in an excess of medium and harvesting (often quite aggressively) just before the point of medium exhaustion is quite an unphysiologic process. Popular culture systems often take cells that originally grew attached to a porous matrix at high densities, with little variability in nutrient and oxygen supply, and…

Rethinking Media Performance

    Fetal bovine serum (FBS) was — and in many cases still is — the supplement of choice to maintain the viability of mammalian cells in culture. However, there are considerable limitations to its use. In the early days of cell culture, the issues surrounding serum were mainly its variable performance and the potential to contaminate cultures with fungi, viruses, and bacteria. Early attempts to produce a serum-free medium (SFM) were academic exercises that usually relied on the use…

Maintaining Product Titer While Replacing Undefined Components in a CHO Culture System

    Proteins, hydrolysates, and lysates of plant or yeast origin are commonly used in cell culture media for large-scale manufacturing processes for human biotherapeutics. Lot-to-lot variability in the composition of such constituents is well established and can affect multiple biological performance indicators. Our goal was to replace an undefined, protein-containing medium with a chemically defined medium (meaning the chemical structure and concentration for each component in a formulation is known). Such a formulation should be free of protein and…

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…

New Validation Guidance Causes a Stir

In November 2008 the US FDA finally issued a new draft guidance on process validation (1). The original guidance on this topic was published in May 1987, and the FDA explained that “since then, we have obtained additional experience through our regulatory oversight that allows us to update our recommendations to industry on this topic.” The new guidance is intended to reflect some goals of the FDA’s Pharmaceutical GMPs for the 21st Century, an initiative that was finalized in 2004.…

Applying Intelligent Flow Microscopy to Biotechnology

Ongoing requirements for additional insight and CGMP-compliant measurement have led to interest in new technologies that can be applied to the analysis of many different types of particle-containing fluids. Micro-Flow imaging (MFI) is a robust, versatile, and intelligent vision technology that is increasingly used for evaluating populations of microparticles encountered during bioformulation development (1). It is also being accepted in fill–finish processes and many other biotechnology applications. Features of MFI technology that have contributed to its rising popularity include the…

Development and Qualification of a Generic IgG Quantification Assay Using Surface Plasmon Resonance

Fast, precise, and accurate quantification technologies are indispensable for efficient process development in applications such as IgG production in a GXP environment. Based on surface plasmon resonance (SPR) technology, the Biacore C system from GE Healthcare (www.biacore.com) is an alternative technology for IgG quantification that has benefits over traditional methods. Assay development is simplified and accelerated due to real-time detection. Assay hands-on time is reduced, and sample throughput can be increased using automation and efficient data evaluation with regulatory-compliant software.…

Automated Liquid Handlers As Sources of Error

Use of automated liquid handling equipment for rapid testing and reproducible screening of thousands of molecules, cells, and compounds has become an essential component of life-science laboratories across the globe. Along with an increase in such use, transferred volumes have shrunk, as demands increase on transfer accuracy and precision when aspirating, diluting, dispensing, mixing, and washing. Automated liquid handlers are generally used to increase the productivity and repeatability of volume transfer, but as discussed here, they are still prone to…

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…