Integrated Process Model Applications Linking Bioprocess Development to Quality by Design Milestones.

Maximizing the value of each available data point in bioprocess development is essential in order to reduce the time-to-market, lower the number of expensive wet-lab experiments, and maximize process understanding. Advanced in silico methods are increasingly being investigated to accomplish these goals. Within this contribution, we propose a novel integrated process model procedure to maximize the use of development data to optimize the Stage 1 process validation work flow.

Size distribution analysis of influenza virus particles using size exclusion chromatography.

Size exclusion chromatography is a standard method in quality control of biopharmaceutical proteins. In contrast, vaccine analysis is often based on activity assays. The hemagglutination assay is a widely accepted influenza quantification method, providing no insight in the size distribution of virus particles.

Mono- and polyprotic buffer systems in anion exchange chromatography of influenza virus particles.

Different ions typically used in downstream processing of biologicals are evaluated for their potential in anion exchange chromatography of an industrially produced, pandemic influenza H1N1 virus. Capacity, selectivity and recovery are investigated based on single step elution parallel chromatography experiments. The inactivated H1N1 feedstream is produced in Madin-Darby Bovine Kidney cells.

Routes to improve binding capacities of affinity resins demonstrated for Protein A chromatography.

Protein A chromatography is a well-established platform in downstream purification of monoclonal antibodies. Dynamic binding capacities are continuously increasing with almost every newly launched Protein A resin. Nevertheless, binding capacities of affinity chromatography resins cannot compete with binding capacities obtained with modern ion exchange media.

Kinetic plots in aqueous size exclusion chromatography of monoclonal antibodies and virus particles.

The growing importance of monoclonal antibodies and virus particles has led to a pressure for faster size exclusion chromatography. In recent years, numerous small particle columns for size exclusion chromatography of biologicals have been introduced. Small particles are a strategy to reduce analysis time.

Dual salt mixtures in mixed mode chromatography with an immobilized tryptophan ligand influence the removal of aggregated monoclonal antibodies.

In downstream processing of monoclonal antibodies, proper aggregate removal is crucial. Mixed mode ligands such as immobilized tryptophan have been developed to satisfy the need for efficient removal of antibody aggregates. However, method development for mixed mode applications is complicated, since protein binding and elution can be modulated by an increased set of parameters.

Mixed electrolytes in hydrophobic interaction chromatography.

An essential part of the modulation of protein-binding capacity in hydrophobic interaction chromatography is the buffer-salt system. Besides using "single" electrolytes, multicomponent electrolyte mixtures may be used as an additional tool. Both the protein solubility and the binding capacity depend on the position of a salt in the so-called Hofmeister series.