Optical Character Recognition and Code Verification

Nov 01, 2011

Inspection systems play a big part in ensuring product quality. This can range from systems that check fill levels and integrity of seals on vials and bottles, through systems that check that correct, unbroken tablets are loaded into blister packs, to assembly verification systems that will check that the correct label is on a package and that it is assembled with the correct leaflet and inserted into the correct outer packaging. In this context visual inspection, or machine vision, systems improve quality and manufacturing yield by monitoring processes and detecting assembly errors.

With the wide adoption of pharmaceutical unit level traceability or serialisation, Optical Character Recognition (OCR) can help to ensure patient safety and reduce counterfeit drugs from entering the supply chan. OCR technology enhances patient safety by ensuring that all critical information (e.g., product lot and batch information) is clear and legible for patients to read. Such information is crucial in the event of a product recall. An OCR system is used at the pharmaceutical packing facility to read and verify the correctness and legibility of important information, and to record lot and batch numbers for traceability.

There are also new initiatives that aim to provide pharmaceutical packages with a unique identity—a serial number at the individual package or dose level. In this context, OCR can identify the individual package and trace its progress throughout the supply chain to the point of sale or dispense.

When implementing OCR, companies first need to consider whether they are implementing the technology for internal process improvements or to meet mandated requirements. If the implementation is required to comply with mandated traceability requirements, they need to ensure that the visual recognition system complies with the necessary requirements. Furthermore, companies need to consider how this system can be updated should any of these requirement change.

The most important factor to consider when monitoring the quality of barcodes or other symbols is verifying the quality according to the appropriate or mandated standard or, if you are verifying the marks, to ensure they will be readable within your traceability project. Barcode verification is mandated through adopted industry standards such as IS015415, AS9132 and AIM DPM -1-2006. These standards are typically required by regulators to ensure that the barcode is readable throughout the tracking process. Standards such as the AIM DPM 1-2006 specify multiple different lighting techniques to allow for the correct lighting for the type and mark being verified. It also requires the verification system to be calibrated, with specific aperture and focus settings. These specifications are required to ensure verification and repeatability, and consistency from barcode to barcode.

If a company’s verification objective is to ensure that you never make a bad mark, then it is up to the company to decide on the best approach to meet this objective.

A barcode verifier should be used at your marking point to monitor the marking process. Properly used, a verifier can determine when your marking process begins to slip in quality. This allows you to adjust the marker well before it makes a bad mark—it is too late to find out somewhere down the line that your printer or laser marker is making unreadable marks. At this point, you will be required to stop the marking process, quarantine the bad barcodes and remark all affected items with. With a verifier at the point of marking, you can constantly monitor the process and be notified as soon as the marker begins to drift out of specification.