LMWH Concentration Measurement via 1,9-Dimethyl-Methylene Blue

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Solution Overview

Problem

Current methods for measuring low molecular weight heparin (LMWH) concentrations in solutions are inaccurate, impractical, and not amenable to high-throughput analysis, particularly due to weak UV signals and lack of specificity in existing techniques.

Innovation Solution

A method using 1,9-dimethyl-methylene blue to determine LMWH concentrations by reacting samples with the dye and comparing absorbance to standard curves of known concentrations, allowing for accurate, quick, and high-throughput quantification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If UV absorption methods are used to measure LMWH concentration, then measurement can be performed, but the UV signal is very weak and nearly undetectable

Engineering Contradiction:
Improvedetection sensitivityVSAvoidweak UV signal
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses a colorimetric reagent as an intermediary substance that reacts with LMWH to produce a colored complex. This mediator converts the undetectable UV signal into a visible color change that can be easily measured, thereby resolving the detection sensitivity problem without requiring sensitive UV detection equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention employs a colorimetric assay where the color intensity of the LMWH-reagent complex is directly proportional to the LMWH concentration. By measuring color change rather than weak UV absorption, the method achieves high detection sensitivity and accuracy, directly addressing the technical contradiction between detectability and signal strength.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If UV absorption methods are used, then concentration measurement is possible, but large amounts of test material are required making them impractical

Engineering Contradiction:
Improveconcentration measurementVSAvoidtest material volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent changes the measurement parameter from UV absorption (which requires large sample volumes) to colorimetric measurement at visible wavelengths. This parameter change allows the same concentration measurement to be achieved with much smaller sample volumes, making the assay practical for limited test materials while maintaining measurement precision.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If refractive index-based techniques are used, then measurement can be performed, but they lack specificity and result in artificially high results

Engineering Contradiction:
Improvemeasurement speedVSAvoidmeasurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The colorimetric reagent is designed to specifically bind to the unique pentasaccharide sequence in LMWH, creating a localized specific interaction. This specificity ensures that only LMWH molecules with the correct structure produce a color response, eliminating the false positives and artificially high results that plague non-specific refractive index methods while maintaining rapid measurement capability.

Inventive Principle:
Principle #3Local quality

4Measurement precision

If conventional measurement methods are used, then analysis can be performed, but they are not amenable to high-throughput quantitative assay format

Engineering Contradiction:
Improvequantitative accuracyVSAvoidthroughput capacity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The colorimetric assay design allows it to function across multiple formats and scales - from individual sample analysis to high-throughput plate-based screening. The same fundamental reaction and measurement principle work whether analyzing one sample or hundreds, enabling the method to maintain quantitative accuracy while achieving high throughput capability that conventional methods cannot match.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 provides accurate, quantitative, and rapid measurement of LMWH concentrations, suitable for pharmaceutical manufacturing and research, ensuring precise monitoring and cleaning of manufacturing equipment to achieve acceptable residual concentrations.

Implementation Method 1

determining the absorbance of the sample reacted with 1,9 dimethyl-methylene blue

Methodology Applied
Scientific EffectAbsorption Spectroscopy: Absorption Spectroscopy

Implementation Method 2

reacting the sample with 1,9-dimethyl-methylene blue; and determining the absorbance

Methodology Applied
Scientific EffectColorimetric reaction: Absorption (EM radiation)

Data Source

PatentEP2191278B1Method for measuring the concentration of a glycosaminoglycan anticoagulant
Publication Date: 2013.09.04 ACTIVE BIOMATERIALS LLC
  • EP2191278B1 patent drawingFigure 1
  • EP2191278B1 patent drawingFigure 2
  • EP2191278B1 patent drawingFigure 3

AI summary

The invention provides an accurate, economical, automatable, high throughput method for the determination of the concentration of glycosaminoglycan anticoagulants, including low molecular weight heparin (LMWH) anticoagulants, in aqueous solutions. A method for cleaning a unit of manufacturing equipment used in the preparation of a LMWH to obtain an acceptable residual concentration of LMWH is further provided. The method makes use of 1, 9-dimethylmethylene blue.