SEC–ESI-MS Dimer Analysis for Heterodimer Quantitation

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Solution Overview

Problem

Existing methods struggle to accurately identify and quantify dimer species, particularly heterodimers, in co-formulated protein biopharmaceutical products, which are challenging due to the complexity of protein formulations and the need for high sensitivity and resolution in analytical characterization.

Innovation Solution

A method combining chromatography with electrospray ionization mass spectrometry and immunoprecipitation, utilizing a chromatographic system with a chromatography resin and electrospray ionization mass spectrometer, along with a stable isotope labeling technique, to identify and quantify dimer species, including heterodimers, in co-formulated preparations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional size exclusion chromatography is used to analyze co-formulated drugs, then the analysis can be performed with simple equipment, but the method cannot achieve sufficient resolution to differentiate and quantitate different dimer forms

Engineering Contradiction:

Improveresolution to differentiate dimer formsVSAvoidcomplexity of analytical system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines size exclusion chromatography (SEC) with electrospray ionization mass spectrometry (ESI-MS) to create a hybrid analytical system. The SEC component provides separation of dimer forms based on size, while the ESI-MS component provides precise mass measurement and identification. This merging allows differentiation of heterodimers from homodimers with high resolution while maintaining the simplicity of the overall approach.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediary coupling system between the chromatography column and mass spectrometer, including a flow splitter and nanospray interface. This intermediary enables the transition from liquid chromatography flow to gas-phase ionization suitable for mass spectrometry, allowing the combination of separation and detection capabilities without direct mechanical integration.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If direct analysis is performed to detect impurities in co-formulated drugs, then the analysis can be completed quickly, but sufficiently large amounts of product isolation are required which is undesirable

Engineering Contradiction:

Improveamount of product required for analysisVSAvoidtime for product isolation

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The patent extracts only the essential detection function from the overall analysis process by using online ESI-MS detection directly coupled to SEC. This eliminates the need to isolate and concentrate large amounts of product that would be required for traditional offline analytical methods. The mass spectrometer detects impurities directly in the chromatographic effluent with high sensitivity, requiring minimal product quantity.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If co-formulation of multiple therapeutic monoclonal antibodies is implemented, then patient convenience and compliance are improved, but the analytical characterization becomes significantly more challenging due to formation of heterodimer species

Engineering Contradiction:

Improvecapability to characterize heterodimer speciesVSAvoidcomplexity of formulation system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical separation and identification methods with mass spectrometric detection. Instead of relying on physical separation techniques that cannot resolve heterodimers from homodimers, the ESI-MS system uses mass-to-charge ratio measurement to directly identify and quantify different dimer species based on their distinct molecular masses, providing unambiguous characterization.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The method provides precise identification and quantification of dimer species, enhancing the characterization of co-formulated protein biopharmaceutical products by differentiating between homodimers and heterodimers, ensuring high purity and stability of the final product.

Implementation Method 1

contacting a sample including the dimer species to a chromatographic system with a chromatography resin, washing said resin using a mobile phase to provide an eluent including the dimer species

Methodology Applied

Scientific EffectChromatography: Chromatography

Implementation Method 2

identifying the dimer species in said eluent using an electrospray ionization mass spectrometer

Methodology Applied

Scientific EffectElectrospray ionization: Electrostatic Induction

Data Source

PatentUS12399182B2Quantitation and identification of dimers in co-formulations

Publication Date: 2025.08.26 REGENERON PHARMACEUTICALS INC

AI summary

Methods and system for identification of dimer species using online chromatography and electrospray ionization mass spectrometry are provided. Also provided are methods and system for quantitation of heterodimer species using immunoprecipitation and liquid chromatography-mass spectrometry.