Impedance-Based Reconstitution Detection in Pharmaceutical Containers

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Solution Overview

Problem

Current methods for determining the completion of reconstitution of pharmaceutical solutions are subjective and imprecise, relying on human visual inspection, which leads to variability in reconstitution times and potential undissolved particles in solutions.

Innovation Solution

A method using impedance or resistance measurements to objectively determine when reconstitution is complete, by selecting a predetermined amount of solid and liquid substances, measuring changes in impedance or resistance within a defined threshold, and correlating these measurements with the concentration of the solid substance over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If human visual inspection is used to determine reconstitution completion, then the method is simple to implement, but the measurement precision and reliability are poor due to subjectivity

Engineering Contradiction:
Improveease of implementationVSAvoidreconstitution completion detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/visual inspection system with an electrical measurement system. Impedance or resistance measurements are used to objectively detect reconstitution completion, eliminating subjective visual assessment. The system measures electrical properties of the solution to determine when the solid substance is fully dissolved, providing precise and repeatable results without human intervention.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an electrical measurement intermediary (impedance/resistance measurement system) between the reconstitution process and the determination of completion. This intermediary provides an objective, quantifiable signal that correlates with the dissolution state, allowing precise detection of reconstitution completion without direct visual inspection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If human visual inspection is used to determine reconstitution completion, then no additional equipment is needed, but the reliability and consistency of reconstitution times vary significantly

Engineering Contradiction:
Improveequipment requirementsVSAvoidreconstitution time consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces the human visual inspection system with an automated electrical measurement system. Impedance or resistance measurements provide consistent, objective data that eliminates variability between different operators and ensures reliable, repeatable reconstitution time determination across multiple preparations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism where impedance or resistance measurements are continuously monitored during reconstitution. The system provides real-time information about the dissolution progress, allowing for precise determination of completion point and ensuring consistent reconstitution times through objective feedback rather than subjective visual assessment.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If impedance or resistance measurements are used to determine reconstitution completion, then the measurement precision and reliability are improved, but the device complexity increases

Engineering Contradiction:
Improvereconstitution completion detection accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex visual inspection protocols with a relatively simple electrical measurement system. Impedance or resistance measurements using basic electrical circuits provide objective, precise detection of reconstitution completion with minimal equipment complexity compared to the time and subjectivity involved in visual inspection methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If automated impedance measurement is implemented, then the productivity and consistency of solution preparation are improved, but the ease of operation decreases due to additional measurement procedures

Engineering Contradiction:
Improvesolution preparation efficiencyVSAvoidoperational simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements a self-service system where the impedance or resistance measurement automatically determines reconstitution completion without requiring human judgment. The system performs the measurement and provides objective data about completion status, eliminating the need for operators to visually inspect and interpret solution clarity, thereby improving productivity while maintaining operational simplicity.

Inventive Principle:
Principle #25Self-service

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 an automated, accurate, and objective assessment of reconstitution completion, reducing variability and ensuring the absence of undissolved particles, thus improving the reliability of pharmaceutical solution preparation.

Implementation Method 1

measuring a value chosen from impedance or resistance of the solution in the container

Methodology Applied
Scientific EffectElectrical impedance: Electrical Impedance Tomography

Implementation Method 2

measuring a value chosen from impedance or resistance of the solution in the container

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP3161466B1Method for determining whether reconstitution of a solution in a container is completed
Publication Date: 2023.06.21 F HOFFMANN LA ROCHE & CO AG
  • EP3161466B1 patent drawingFigure 1
  • EP3161466B1 patent drawingFigure 2
  • EP3161466B1 patent drawingFigure 3~4

AI summary

A method for determining whether reconstitution of a solution (6) in a container (1) is completed comprises the steps of: - selecting a predetermined amount of a solid substance (2) and a predetermined amount of a liquid solvent (5) from which the reconstituted solution (6) is to be prepared, - preparing a solution (6) by solving the predetermined amount of the solid substance (2) in the predetermined amount of the liquid solvent (5), - measuring the impedance (Z) or the resistance (R) of the solution (6), - determining whether the change of the measured impedance (Z) or the resistance (R) within a measuring time interval of a predetermined duration is below a defined threshold, and determining that reconstitution of the solution (6) is completed when the change of the measured impedance (Z) is below the defined threshold.