LRV Determination for Size-Exclusion Virus Filters
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Solution Overview
Problem
Current methods in virus-depletion studies fail to accurately distinguish between virus retention mechanisms of prefilter and virus filter, leading to unclear mechanisms of action and overestimation of virus depletion, especially when using adsorbing prefilters that are not compatible with in-line processes.
Innovation Solution
A method to determine the logarithmic reduction value (LRV) of a size-exclusion filter protected by a process adsorber, involving a test system with a test adsorber that retains fewer particles than the process adsorber, allowing for the separation of adsorption and size exclusion mechanisms, enabling a more accurate representation of production-scale virus-depletion studies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a process adsorber is used to protect the size-exclusion filter from blocking adsorbing species, then the filter reliability is improved, but the measurement precision of virus retention is worsened due to inability to distinguish adsorption from size exclusion mechanisms
Solution Approach 1:
The invention segments the virus retention measurement into two distinct components by using a test adsorber with different properties than the process adsorber. By measuring the LRV of the test adsorber separately and subtracting it from the combined LRV of the test system, the contribution of adsorption is isolated and removed, leaving only the size exclusion mechanism of the virus filter. This segmentation allows precise measurement of the virus filter's performance independent of adsorption effects.
Solution Approach 2:
The test adsorber serves as an intermediary element that mimics the adsorption behavior of the process adsorber but with known, controllable properties. This intermediary allows the measurement of adsorption effects separately from size exclusion effects, enabling accurate determination of the virus filter's true performance without the confounding influence of unknown adsorption mechanisms.
2Reliability
If a prefilter is used in virus-depletion studies, then the protection of the virus filter is improved, but the accuracy of virus depletion assessment is worsened due to overestimation of virus retention
Solution Approach 1:
The invention extracts the adsorption component from the overall virus retention measurement by using the test adsorber as a reference. The LRV contribution from adsorption (measured by the test adsorber) is taken out from the total LRV of the test system, leaving only the size exclusion component that accurately reflects the virus filter's performance. This extraction eliminates the overestimation problem caused by including adsorption effects in the virus depletion assessment.
3Duration of action of stationary object
If adsorbing prefilters are used in virus-depletion studies, then the filter service life is improved, but the mechanism identification is worsened due to unclear distinction between adsorption and size exclusion
Solution Approach 1:
The invention introduces a dynamic measurement approach where the test adsorber can be selectively used or bypassed depending on the measurement objective. By dynamically adjusting whether the test adsorber is included in the measurement path, the method can separately quantify adsorption effects and size exclusion effects, providing clear mechanism identification while maintaining the protective function of the adsorbing prefilter in the actual process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for precise determination of virus retention originating solely from the virus filter, unambiguously identifying the mechanisms of action and providing a realistic representation of production-scale processes, thereby improving the accuracy of virus-depletion studies.
Implementation Method 1
a process adsorber which protects a size-exclusion filter from a blocking adsorbing species present in a process solution to be clarified
Implementation Method 2
a virus filter, which only retains the viruses according to the principle of size exclusion
Data Source
AI summary
The present invention relates to a method for determining the logarithmic reduction value LRV of a size-exclusion filter for a particle of a process solution, which particle is to be clarified, the size-exclusion filter being protected from a blocking adsorbing species present in the process solution by a process adsorber which is connected upstream in series.