X-Ray Inspection Helps Pfizer

Francisco Collazo, technical service specialist at Pfizer, noticed that one of the company’s OTC blister packaging lines had a problem with broken tablets and occasionally crushed or folded blister packs inside the packaging. Neither the vision system nor the checkweigher was finding these defects.


Pfizer installed a Mettler-Toledo Safeline PowerChek x-ray inspection system that not only detected and rejected multiple contaminants, but also verified product and package integrity. Tablets are dropped into formed plastic blisters and sent through a vision system that checks that all tablets are present. After the printed foil is sealed to the plastic web, the blister pack goes through a perforator and is then cut into desired pack sizes and dropped into a sorter that can be set into stacks of one, two, or four. Running at up to 300 packs per minute, it then is put into the final packaging and through the PowerChek x-ray unit where any packages with broken, damaged, or missing tablets or crushed blisters are air-jetted into a separate lockable bin for analysis.


“When we were searching for an x-ray system, we turned to Mettler-Toledo Safeline because it was the only manufacturer that could inspect blister packs stacked up to four deep,” says Collazo. “All other systems would only guarantee two layers.”


The key benefits of using modern detection systems are that defects and contamination are found and rejected automatically.
The Safeline PowerChek x-ray system features superior image processing technology that optimizes the performance of the system. Pfizer runs 13–15 different over-the-counter products on the production line. Because the system stores multiple product profiles, product changeover takes only seconds. The system continuously analyzes product variations and automatically adjusts to achieve optimum sensitivity and eliminate false rejects. A high-resolution color screen provides a visual reference of the machine’s operation using video images and provides real-time diagnostics.


In a milling room where the powders are combined, Pfizer installed a Safeline PharmaGF metal detector that detects and rejects all metal types on the free-flowing powders. In the tableting rooms, they have multiple Safeline Tablex units that detect and reject ferrous, nonferrous, and stainless-steel contaminants directly following the tableting press. As a result, most metal contaminants are rejected from product prior to the packaging line.


“There are almost no false rejects,” says Collazo. “Sometimes we open the package and have to shake it to find that the system identified a tablet that was shaved off on the opposite side of the tablet. We would never have been able to see it.”


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