Viral clearance evaluation for biological medical product preparation processes

Inventors

Olszowy, Michael W.

Assignees

Sartorius Stedim North America Inc • Sartorius Bioanalytical Instruments Inc

Abstract

Fluorescent viral particles, including viral particles and a fluorescent dye conjugated to the viral particles, are used for viral contaminant removal testing as part of viral clearance evaluation for biological medical product preparation processes. The conjugated fluorescent dye adds only marginally to viral particle size, but provides versatility both for rapid screening of alternative viral removal approaches during process development and for final process validation, as the fluorescent viral particles have fluorescent activity throughout the viral clearance evaluation process, permitting rapid and consistent quantification of initial test solutions, resulting purified solutions, and intermediate solutions of interest at any point during processing under evaluation.

Core Innovation

The invention relates to fluorescent viral particles, where viral particles are covalently conjugated to fluorescent dyes and used as test contaminants to evaluate viral clearance in biological medical product purification processes. The fluorescent viral particles enable fluorescence-based quantification during purification, including feed, intermediate, and treated solutions, without requiring post-purification fluorescent staining.

The invention provides determining a degree of removal by comparing the evaluation solution and the treated solution for fluorescent viral particles. The residual concentration of fluorescent viral particles is determined by flow cytometry that detects a fluorescent emission signature of the fluorescent dye conjugated to the viral particles, and after the purification process no additional fluorescent stain is added to the treated solution prior to the flow cytometry.

The invention further enables rapid screening and validation using pre-packaged, analytically quantified viral standard solutions in sealed containers with exteriorly observable indicia. Multiple fluorescent viral particles or dyes may be used for multiplexing with multiple fluorescent emission signatures, and a kit concept is described that can include viral standard products and viral removal devices.

Claims Coverage

The partial content includes three independent claims that share a common inventive framework: fluorescent viral particles are used as a viral contaminant, viral removal is performed as part of a purification process, and the degree of removal is determined by flow cytometry via detection of a fluorescent emission signature of a fluorescent dye conjugated to the viral particles, with an explicit requirement that no additional fluorescent stain is added after purification and prior to flow cytometry. Each independent claim includes multiple inventive features, including the purification-to-treated-solution comparison and the flow-cytometry-based quantification of residual concentration, and one claim also determines feed concentration.

Across the independent claims, viral clearance evaluation is performed by purifying an evaluation solution containing fluorescent viral particles using a viral removal technique, creating a treated solution, and determining the degree of removal by flow cytometry detection of the fluorescent dye emission signature to analytically quantify the residual fluorescent particle concentration, with the requirement that no additional fluorescent stain is added after purification prior to flow cytometry. One independent claim additionally determines a feed concentration and a residual concentration for the degree of removal.

Stated Advantages

Documented Applications