The conclusion of this CMC Forum continued to focus on the latest developments in detection and characterization of protein aggregates (1). Afternoon sessions detailed the most recent experiments probing the role of protein aggregates in immunogenicity, with discussions on the best models to use and initial results. Topics included potential thresholds for immunogenicity, linking laboratory and clinical data, and predicting and testing potential immunogenicity of products throughout a development lifecycle. Afternoon Sessions Amy Rosenberg (Division…
Author Archives: Russell Madsen
Analysis and Immunogenic Potential of Aggregates and Particles
The number of biotherapeutics on the market has rapidly increased during the past several years. Such proteins commonly exhibit a concentration-dependent propensity for self-association, which often leads to the formation of aggregates that range in size from nanometers (oligomers) to microns (subvisible and visible particles). Publications two years ago focused attention on the potential immunogenicity of active-ingredient aggregates ((1,2,3,4). The authors discussed lack of specificity of compendial measurements and inability of other current methods to address potential effects…
How Pore and Fibrous Interstice Structure Influence Filter Performance
When bioprocess liquids bearing suspended particles are filtered, retained particles can block and clog membrane filter pores. The pore size rating of a filter should be selected to retain objectionable particles by sieving, and the aptitude of its polymeric composition for adsorptive sequestration of those particulates also needs to be known. The quantity and nature of retained particles require accommodation if filtrative removal is to be considered successful. Too extensive a particle load will prematurely block a filter’s…
How Pore and Fibrous Interstice Structure Influence Filter Performance
A common objective in pharmaceutical processing is the removal of solids from fluid suspensions through filtration. The usual purpose is the removal of the solid particles to a specified extent, within a given time interval, at the largest possible throughput. Attainment of those goals is managed by proper selection of filtration conditions: principally an adequate effective filtration area (EFA) as defined by filter porosity and a proper rate of flow as regulated by applied differential pressure (ΔP) over…