Container Permeability Testing via Humidity Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for checking the tightness of closed containers for pharmaceutical active substance formulations are time-consuming and often require high helium concentrations, limiting their applicability and reproducibility, especially for containers that are inherently tight.
Innovation Solution
A method involving charging a closed container with a gas and using a porous solid body, such as clay, to absorb and analyze the permeating liquid, allowing for quick determination of permeability rates by measuring the increase in gas composition, which is independent of permeation direction and can detect small amounts of liquid or gas in the ppb range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional tightness checking methods (weight gain measurement, helium leak detection) are used, then container tightness can be determined, but the measurement process is time-consuming (months for weight gain method) or requires high helium concentrations that are difficult to achieve consistently in production
Solution Approach 1:
The invention changes the measurement parameter from weight gain (taking months) or helium concentration (requiring high levels) to water vapor concentration in the headspace gas. By using a humidity sensor to detect water vapor ppm levels, the measurement can be completed quickly while maintaining high precision in detecting tightness, even for inherently tight containers.
Solution Approach 2:
The invention replaces the mechanical weight gain measurement method with a gas phase humidity detection method. Instead of measuring mass change over months, the system analyzes the composition of the headspace gas using a humidity sensor, substituting mechanical measurement with chemical/compositional analysis for faster results.
2Reliability
If high helium concentration is used in leak detection, then reproducible results can be obtained, but it is not always easy to achieve consistent high helium concentration in production process
Solution Approach 1:
The invention changes from requiring high helium concentration to requiring only normal atmospheric conditions with controlled humidity. The humidity sensor can detect water vapor at ppm levels in air, eliminating the need to achieve and maintain high concentrations of a specific gas, thereby improving ease of manufacture while maintaining reliability.
Solution Approach 2:
The measurement system uses the ambient air and natural water vapor present in the container headspace, rather than requiring introduction of a specific test gas. The system serves itself by detecting the naturally occurring water vapor that results from any leakage, eliminating the need for complex gas introduction and concentration control systems.
3Measurement precision
If gas escape detection methods are used for inherently tight containers, then tightness can be measured, but only very little gas escapes making detection difficult below the detection limit of the measuring chamber
Solution Approach 1:
The invention changes the detection parameter from absolute gas concentration to relative humidity measurement. The humidity sensor can detect water vapor at ppm (parts per million) levels, providing high sensitivity for detecting very small amounts of gas escape from inherently tight containers, far below the detection limits of conventional measuring chambers.
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 rapid and reproducible data on container tightness, reducing measurement time and environmental influence, while being applicable to various container types and formulations, including blisters and inhaler cartridges.
Implementation Method 1
the liquid is absorbed by a porous solid body (10) placed in the container (3)
Implementation Method 2
an increase in the amount of liquid in the gas is then analyzed
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for checking the permeability rate of a sealed container (3) to a medium, in particular, a film container for housing a pharmaceutical agent formulation, wherein the container is filled with the medium (3), subjected to a gas and a subsequent increase in the amount of medium in the gas analysed.