The days of testing for leaks in blister packs with traditional blue dye are numbered at Pfizer, which has replaced the method with high-tech scans.
Sepha, a Northern Irish manufacturer of high resolution imaging machines, told in-Pharmatechnologist.com it signed a $1.5m (€1.1m) contract to supply its VisionScan technology to Pfizer. The equipment has been installed at sites in Asia, Europe and North America, with South American facilities to follow shortly, said Paul Kelly, Marketing Manager, Sepha.
Using a vacuum chamber and imaging software, the scanner replaces the traditional manual test for blister pack faults which uses water baths or dye.
High resolution imaging
The VisionScan instrument works by inserting a blister pack into a chamber and applying a vacuum, Kelly told us. “What should happen is the pockets of foil or PVC should swell and rise up. We have pre-created a recipe for how it should perform.
“We project light into the chamber and we take reference images – and the software compares the images. Any deviations to the standard recipe will come up as a ‘gross failure’ or a ‘decay failure’.” A gross failure indicates a large hole and a decay failure is a more minor fault that is revealed over time.
The equipment is sensitive down to faults of about 15 microns, said Kelly, “whereas blue dye is good to about 30 microns, and after that sensitivity starts to diminish.”
‘Messy, dirty, wasteful’
Using traditional statistical batch analysis, manufacturers pick a dozen packs from their production line every 15 to 30 minutes for testing. The result is “messy, dirty and wasteful,” said Kelly, since testing destroys packs and they must be thrown away.
Imaging technology means “you’re not wasting water, you’re not flushing blue dye, and there’s no packaging waste in a landfill,” he said.
When failed packaging is discovered, the tablets can still be recovered using “deblistering” equipment, he continued, and added back into the production line.
While the initial outlay for VisionScan is much greater than for dye methods, companies see a return on investment in less than two years, Kelly told us, although he admitted “if you’re working on really cheap products like aspirin, it’s very difficult to justify” the cost.
Companies make savings via recovery of their product with the imagine technology, he said, adding Pfizer is “actually starting to roll this out in their emerging markets first because they’re looking for cost improvements in those areas.”