Dr. Dorian Dixon, packaging specialist and senior lecturer in the School of Engineering at Ulster University, has published a new white paper that confirms the Sepha VisionScan is a non-destructive method to test the integrity of pharmaceutical blister packs. A stability study was conducted to test the hypothesis there is no significant increase in the moisture status of tablets inside a blister pack inspected by the VisionScan test method compared to blister packs in the control group.
These findings will interest those in the pharmaceutical packaging industry as the non-destructive claims of the Vision with Vacuum method are now backed up by independent, statistical data. This gives companies that are considering alternative solutions to destructive methods including blue dye, a validated and deterministic solution that will enable them to reduce production cost as the packs that passed the test can be returned to the line and material and product disposal / incineration cost will be vastly reduced.
The VisionScan, developed by engineering company Sepha, tests the integrity of blister packs using vision and vacuum technologies. The method works by creating a vacuum around a blister pack while a high-resolutions imaging system monitors changes in individual blister pockets. Any difference in pocket shape which deviates from the expected behaviour when establishing the vacuum, or during the dwell time of the vacuum, indicates leakage of air from the blister pack. The tool-less system can identify leaks in individual pockets down to 7µm and offers manufacturers a non-destructive, deterministic, reliable and repeatable solution.
To test if blister packs inspected with the Sepha VisionScan are in any way comprised by the test method itself, a stability study was conducted by independent research company Relequa. Using its Moisture Profiling™ technique, the company investigated the barrier performance of blister packs made with different material types, by measuring the moisture levels of the tablets over a 12-week period. A breach of seal integrity will expose the tablets to external humidity which will result in higher moisture uptake.
Xylitol tablets were sealed inside blister packs with three different material types including:
- PVDC coated PVC blister sealed with aluminium 20µmhard lidding material
- Aclar® (PVC/PE/PCTFE)blister sealed with aluminium 20µmhard lidding material
- Aluminium cold formed blister sealed with aluminium foil (Alu/Alu) comprising of a polyamide/aluminium/PVC laminate
For each material type, the blister packs were split into a group of packs inspected with the Sepha VisionScan and a control group not inspected with the VisionScan. All samples were then aged for 12 weeks at two elevated humidity conditions (25°C/60%RH and 40°C/75%RH).
At different time points, tablets were removed from both the inspected and control blister packs and tested for moisture uptake. At the same time positive control packs with 15µm sized defects were tested to measure the effect of exposure to air on the moisture level of the tablets.
The results of the stability study show no significant difference in moisture uptake between the inspected and control blister packs of any of the three types. The tablets from all the blister pack types did show changes in moisture status over time, but the change was consistent for both inspected and control blister packs and were within the expected moisture transmission rate of the materials.
For the positive control, it can be seen the WVEP was typically unreadable indicating the tablets had absorbed very high levels of moisture.
The above results show that the Sepha VisionScan leak test method, does not compromise tablets inside the inspected blister packs and confirms the Vision with Vacuum method truly is non-destructive. Dr Dixon comments: “In my previous White Paper, a study showed that the Sepha VisionScancan identify 100% of defective pockets across a range of blister pack types. Adding the results of this new study proves that the Sepha VisionScan is non-destructive and can offer a significant contribution to the quality control process of pharmaceutical packaging”.
Sepha’s Head of Sales & Marketing, Paul Smith adds: “Although we have full confidence in our technique and system it is great to see the findings of the study confirm our hypothesis. Packaging integrity testing is an essential part of the packaging process, being driven by USP 1207 guidelines, CGMP and ASTM standards. While traditional, destructive methods are still within these guidelines, we see a trend in more companies looking for alternative solutions that have less environmental impact in terms of waste and that can reduce cost in terms of lost products, lost packaging materials and disposal/incineration cost. This new evidence can help these and other pharmaceutical companies as it proves the method does not negatively affect the product inside, enabling manufactures to reuse the products that passed the test and put them back on their line”.
The White Paper can be downloaded on: