Impact of virus preparation quality on parvovirus filter performance

Abstract

Virus-removal filtration technology is commonly used in the manufacturing process for biologics to remove potential viral contaminants. Virus-removal filters designed for retaining parvovirus, one of the smallest mammalian viruses, are considered an industry standard as they can effectively remove broad ranges of viruses. It has long been observed that the performance of virus filters can be influenced by virus preparations used in the laboratory scale studies (PDA, 2010). However, it remains unclear exactly what quality attributes of virus preparations are critical or indicative of virus filter performance as measured by effectiveness of virus removal and filter capacity consistency. In an attempt to better understand the relationship between virus preparation and virus filter performance, we have systematically prepared and analyzed different grades of parvovirus with different purity levels and compared their performance profiles on Viresolve® Pro parvovirus filters using four different molecules. Virus preparations used in the studies were characterized using various methods to measure DNA and protein content as well as the hydrodynamic diameter of virus particles. Our results indicate that the performance of Viresolve® Pro filters can be significantly impacted depending on the purity of the virus preparations used in the spike and recovery studies. More importantly, we have demonstrated that the purity of virus preparations is directly correlated to the measurable biochemical and biophysical properties of the virus preparations such as DNA and protein content and monodispersal status, thus making it possible to significantly improve the consistency and predictability of the virus filter performance during process step validations.

Defining the mechanistic binding of viral particles to a multi‐modal anion exchange resin

“…For example, the isoelectric point estimated for these species range from ∼7.6 to ∼3.9. Typical Capto Adhere chromatography pH operational set points consist of a low of pH 5 and a high of pH 8 . Depending on the chosen pH set point, these viruses could be considered net positively or negatively charged.…”

Mechanistic failure mode investigation and resolution of parvovirus retentive filters

“…At pressure set points P4, P5, and P1 after 10‐min FFI Filter A displayed a significant drop in MMV retention with an LRV of approximately 3.5 log 10 compared with an LRV of 6.5 log 10 at P1 the highest pressure set point. Indeed, evidence suggests MMV is slightly smaller in diameter than PP7 . Thus, it is important to confirm bacteriophage observations with a smaller parvovirus model as it is used to make regulatory claims and may be a more sensitive indicator for breakthrough.…”

Interactions between protein molecules and the virus removal membrane surface: Effects of immunoglobulin G adsorption and conformational changes on filter performance

“…Decreased throughput due to membrane fouling during the production processes is another critical issue in virus filtration . Membrane fouling is commonly observed regardless of filter type and two main causes for the related decline in filter performance have been proposed . First, the adsorption of proteins onto a wide variety of membrane surfaces (caused by protein‐surface interaction) reduces the effective size of the membrane pores and causes caking on the membrane surface.…”

“…Several other studies have discussed the effect of fouling on the decline in virus filter performance with respect to the above two causes. However, most have been devoted to explaining the flux decline induced by the stacking of multimeric protein aggregates on the membrane surface . Brown et al showed that prefiltration using ion exchange membrane absorbers improved virus filter throughput .…”