Printed component verification for pharmaceuticals
It seems like a simple enough task - ensuring that pharmaceutical products are correctly labelled and then packed in the right cartons, along with the appropriate data sheet. However, for Thornton & Ross, the largest independent OTC pharmaceutical manufacturer in the UK and owner of well-known brands such as Covonia, J Collis Browne's and Hedrin, the number of possible combinations of label, carton and Patient Information Leaflets (PIL) runs into thousands.
Though inspections upstream in the supply chain make errors in this area highly unlikely, there is no room for error - for an incorrectly labelled pharmaceutical product, or one that has been packaged with the wrong Patient Information Leaflet, to reach the market is totally unacceptable. As such, the highest level of quality assurance is necessary.
To address this important issue of printed component verification, Thornton & Ross had traditionally used a system of stringent manual checking, complemented by reconciliation counts to ensure, for example, that the number of labels of a particular type that had been used was the same as the number of corresponding products produced. While effective, these methods were tedious and time consuming.
As a result, when the company found that it needed to install new packing machines to cope with the fast growing demand for its products, it decided to look for a better approach to printed component verification. Because Thornton & Ross had a long and successful experience of working with Omron Electronics and using the company's products in packaging and labelling applications, it decided to approach Omron for assistance in developing a solution.
There were two special requirements to be addressed. The first was that any changes to the printed items should not noticeably degrade their appearance - this was particularly important for labels and cartons, which are on public show at the point of sale. The second requirement was that updating the system to cater for new products and changes in existing products should be a fast, easy and reliable process.
The overall concept developed by Omron is straightforward. All printed items - labels, cartons and Patient Information Leaflets - carry an optically readable code. The operator simply tells the machine the type of product that's being handled, and the system verifies the code on every printed item to make sure that the appropriate items are being used for that product.
This provides 100% inspection. Every single printed item for every single product is checked, so that even the most difficult to find problems, such as a single incorrect Patient Information Leaflet inserted in a stack of the correct items, are detected reliably and consistently.
The most obvious way of providing the printed items with an optically readable code was to use barcodes. Unfortunately, however, the codes needed would have occupied a considerable amount of space on the labels and other items and would, therefore, have put further pressure on the available space for essential information. To avoid this DataMatrix two-dimensional codes were adopted as, for a given amount of data, they occupy far less space than conventional barcodes.
Providing reading facilities for the DataMatrix codes was straightforward, as the Omron optical sensor range includes units specifically designed for this application.
Initially, it was envisaged that the information about which labels, cartons and Patient Information Leaflets would be stored locally at each packing machine. This would mean, however, that data for product additions and updates would have to be entered separately at each machine, a process that would be time consuming, especially as Thornton & Ross were expecting to add further machines in the near future to cater for the company's sustained growth.
As a result, Omron, working in conjunction with the Thornton & Ross project team, decided to make use of the Ethernet facilities provided by the CJ1M programmable controllers selected for the project. This allows the printed component verification systems on all of the Thornton & Ross production lines to be networked to a single PC running Omron's Excel based data management software, PLC REPORTER.
The PLC REPORTER software, allows printed component data to be entered and updated via an Excel spreadsheet, which makes the process fast and easy. Once the data has been loaded the updated information is sent to all the network PLC verification systems at the touch of a button.
This approach has the additional benefit that the Ethernet network linking the PC to the programmable controllers has ample spare capacity to cope with the future addition of production lines and packing machines. Further, the PLC REPORTER software can be used to capture and record shopfloor data from the verification system including, for example, production count, downtime and error messages. This captured information can then be inspected via the PC.
The final key item in the project was the provision of a convenient and intuitive operator interface at each packaging machine. For this, Omron NS8 colour touch-screen operator terminals were chosen, with each terminal being linked to the programmable controller that handles the printed item verification on its machine.
The operator terminals provide a detailed realtime display of the status of the verification system, along with information about any errors detected. In addition, they can be used by the operators to enter the identification code for each new batch of product that reaches the machine. These codes are sent via the network to the system's main database, which then returns detailed label, carton and Patient Information Leaflet identification data for the product.
"As might be expected with a project of this complexity, especially as links to our supervisory systems were needed, we had a few minor teething problems in implementation," said Mark Boucherat, Engineering Manager at Thornton & Ross. "However, in many ways these simply emphasised the excellence of the service we receive from Omron, as the company always understood our needs and was always responsive.
"Even for the most searching of queries, Omron was always quick to provide a detailed, useful and accurate answer," he continued. "Once the system was up and running, it quickly proved its worth. Not only does it provide us with useful savings on labour costs, the 100% inspection also provides us with the highest level of quality assurance."
The system has now been in full operation for some time, and has proved completely effective and reliable. In fact, recent calculations by Thornton & Ross show a projected payback period of just 0.81 years for the systems, based solely on the amount of labour costs saved compared with the manual verification systems previously used by the company.
The printed component verification systems based on Omron technology are, therefore, an excellent investment and one that is helping Thornton & Ross to maintain and enhance its position as a leading manufacturer of pharmaceutical products.
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