LIWO test technology for the pharmaceutical sector

The following requirements generally apply to pharmaceutical packagings

Keep product sterile => Avoid penetration of bacteria
Protect product from oxidation => Avoid penetration of oxygen
Protect the environment and man from product => Avoid leakage of active ingredients

Another great challenge in pharmacology in terms of test technology are the high cycle and production rates. LIWO, together with an industrial partner, offers complete test modules for leak/flow/function testing of production rates of up to 500 parts per minute.

Why leak test by detection of nitrogen?

Pressure change methods with air pressure or vacuum do not find small leaks.
Test gas methods (e.g. helium) find small leaks but require a test gas.
In order to get the advantages of both procedures, one needs a test gas method with a test gas present in the package.

Functionality

Vacuum chamber
Gas discharge with nitrogen
Optical spectrometer
Intensity of the nitrogen line is a measure of nitrogen concentration

Sensitivity: 1⋅10^_-6 mbar⋅l/s

Measurement: 1⋅10^_-5 mbar⋅l/s (0,3µm hole diameter)

Advantages over

... Pressure change process

The biggest source of error in pressure change processes is the temperature influence. => Nitrogen detection is independent of the temperature.
The measuring accuracy increases by a factor of 100. This is necessary to be bacterial-dense.
Volume changes are uncritical. => Syringes and blisters are verifiable.
The size of the test chamber is uncritical. => No format parts required.

... Headspace analysis

In the Head Space analysis, penetrated oxygen is detected. Here, the duration of storage between production and test is crucial. => The leak test with nitrogen is independent of the storage period. => The leak testing with nitrogen can be carried out immediately after production or at any later time.

... High voltage testing

The high voltage is only possible on non-conductive packaging. => The leak test with nitrogen is also possible on conductive packaging.
The high-voltage test only works with a conductive liquid in the package. => The leak test with nitrogen also works without liquid in the package.

... Pinhole Detection

The pin hole detection is an optical process and finds holes in foiles.
The method is used successfully to find holes in blister foils before the blister is filled and sealed. The quality of the sealing process can not be recorded. => The leak test with nitrogen checks the complete blister, including the seal seam.

... Blue dye test

The Blue dye test lasts long. => The leak test with nitrogen takes a few seconds.
The Blue dye test contaminates the packaging. => The leak test with nitrogen is clean.
The Blue dye test depends on the operator's judgment. => The leak test with nitrogen is independent of operator influences.
The Blue dye test only detects gross leaks. => The leak test with nitrogen tests bacteria-tight.

... Visual control

The visual control detects only gross leaks. => The leak test with nitrogen tests bacteria-tight.
The visual control is dependent on the judgment of the operator. => The leak test with nitrogen is independent of operator influences.
Visual inspection is only possible with visible defects. => The leak test with nitrogen also works with hidden leaks.

Helium Leak Tester

The helium leakage test is suitable for small leaks. For testing, the packaging must be filled with helium. It must be ensured that helium is still present in the pharmaceutical pack at the time of measurement. This is very complex and partly not permissible.

Example Systems: Single-Use Equipment