With the AMI and its optical emission spectroscopy Pfeiffer Vacuum has introduced a method with lower detection limits compared to any other method that uses gas trapped in the cavity.
The blister package to be tested is put into a test chamber which also provides a viewport and mechanical support for the package. With dimensions of 150 mm x 100 mm x 10 mm, the test chamber is large enough for the biggest blister package available. However, customizations can be made to tailor the chamber to larger samples as well.
After loading the sample, the chamber is evacuated. At pressures lower than 10-2 mbar, a plasma is ignited and its optical emission analyzed with an optical emission spectrometer. The lowest detectable signal corresponds to an orifice diameter of roughly 0.4 µm (for Blister packs) and up to a completely open cavity. The cycle time depends on the desired detection limit. For a defect size of 0.4 µm, a typical cycle time is between 20 and 30 seconds and can be shortened for larger rejection limits.
This method is easy to set up and use and yields quantitative and highly repeatable results. In addition to the information achieved by a simple GO/NOGO test method, the new method of the AMI allows the detection of drifts in sealing parameters in real time. The loss of valuable pharmaceuticals is prevented and production stops for corrective measures are minimized.
Automatic calibration is implemented into the test equipment using certified calibrated leaks. Thereby, operator independent calibration and test results are provided.
The software solutions used in the AMI are compliant with 21 CFR part 11. Optional software solutions are available for a manufacturing execution system. Trend analysis can be implemented in the software for early indication of drift production and packaging equipment.