Printed component verification for pharmaceuticals
August 2011, System Integration & Control Systems Design
It seems simple enough, 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, the number of possible combinations of label, carton and information leaflets runs into thousands. Though inspections upstream in the supply chain make errors in this area unlikely, there is no room for an incorrectly labelled pharmaceutical product, or one that has been packaged with the wrong leaflet. 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 that the number of labels of a particular type 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. The company had a long and successful experience of working with Omron Electronics and 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, particularly important for labels and cartons on public display at the point of sale. The second requirement was that updating the system to cater for new products and changes should be a fast, easy and reliable process.
The overall concept developed by Omron is straightforward. All printed items – labels, cartons and leaflets – carry an optically readable code. The operator simply tells the machine the type of product that is being manufactured and the system verifies the code on every printed item to make sure that only those appropriate are being used.
This provides 100% inspection. Every printed item for every product is checked so that even the most difficult to find problems, such as a single incorrect leaflet inserted in a stack, are detected reliably and consistently.
The most obvious way of providing the printed items with an optically readable code was to use barcodes. Unfortunately, the codes needed would have occupied a considerable amount of space and would have put too much pressure on that available for essential information. To avoid this DataMatrix two-dimensional codes were adopted as for a given amount of data they occupy 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 labels cartons and leaflets would be stored locally at each packing machine. This would mean that data for product additions and updates would have to be entered separately at each machine, a time consuming process particularly as Thornton & Ross were expecting to add further machines in the future to cater for the company’s 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 production lines to be networked to a single PC running Omron’s Excel-based data management PLC Reporter software. The software allows printed component data to be entered and updated via an Excel spreadsheet, making the process fast and easy. Once the data has been entered, the update 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 capacity to cope with future additional machines. Further, the software can be used to capture and record shop floor data from the verification system including, for example, production count, downtime and error messages. This information can then be analysed on 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, each terminal being linked to the programmable controller that handles the printed item verification on its machine.
The operator terminals provide a detailed real-time display of the status of the verification system along with error information. 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 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 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. 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.”
In fact, calculations by Thornton & Ross show a projected payback period of just 0,81 years, based solely on the labour costs saved compared with the manual verification systems previously used by the company. The printed component verification systems based on Omron technology have proved an excellent investment and one that is helping Thornton & Ross to maintain and enhance its position as a leading manufacturer of pharmaceutical products.
For more information contact Terry McIntosh, Omron Electronics, 086 066 7661, firstname.lastname@example.org, www.industrial.omron.co.za