Identifying Marks

Advances in marking, coding, and inspection technology have led to new anticounterfeiting tools for drug makers trying to protect products that are in pill form
Aug 02, 2005


Hallie Forcinio
Solid dosage form manufacturers have long relied on shape and color as well as on-pill imprints of logos, product names, or numbers for product identification. But in these days of heightened counterfeiting concerns, the industry has a growing interest in adding more difficult-to-duplicate features to the pool of existing product identification techniques. Added security is particularly important on high-profile or high-cost drugs, as well as on pharmaceutical products supplied in bulk for repackaging.

Advances in marking, coding, and inspection technology have led to the development of new anticounterfeiting tools for drug makers seeking ways to protect products that are in pill form. The best of these versatile tools help build brand identity and prevent medication errors at the same time by making the product more distinctive.

Because drug makers are always concerned about making postapproval changes to the drug product, the US Food and Drug Administration is working on a guidance that will clarify, and perhaps minimize, notification requirements for manufacturers that want to add anticounterfeiting techniques to their drug products or packaging. The United States Pharmacopeia also has been studying the imprinting of solid dosage forms to identify ways to improve product identification. Its focus, however, appears to be more on improving patient compliance, reducing medication errors, and preventing response delays to poisoning incidents.

Color-changing ink. Some companies are experimenting with using a combination of color-changing materials and laser beams to apply tiny two-dimensional Data Matrix codes or other information such as dosage level directly onto a tablet. The technique, which is patented in Europe and the United States, involves the application of a food-grade, color-changing material as a coating or a coating additive by means of standard spray or tumble methods.

When exposed to a low level of energy from a carbon-dioxide steered beam laser, the color-changing material turns black. These lasers, also known as scribing or vector lasers, operate in the far-infrared range and generate a 10-mm spot of energy. Using this tiny beam, sophisticated control, and appropriate software, drug makers can apply various images including logos, numbers, and Data Matrix codes as small as 0.5-mm square to the product. Codes of this size are difficult for counterfeiters to duplicate. As an additional hurdle for counterfeiters, a different Data Matrix code can be applied to each tablet.

Evaluations of the method are currently underway by pharmaceutical manufacturers and suppliers of coating and tablet production equipment. Commercial applications are expected before the end of 2006. Future developments could result in the application of microscopic photographic images on solid dosage forms, a concept that has already been prototyped. Other advances are likely to center on food-grade formulas that transform into colors other than black when exposed to laser energy (DataLase Edible Laser Imaging Chemistry, Sherwood Technology Ltd., Widnes, UK, http://www.sherwoodtech.com/.)

Microscopic markers. Another way to authenticate solid dosage forms is by means of inexpensive, edible microscopic markers that carry dense, easy-to-read information. Markers are mixed with a liquid coating to enable spray-on application.

Each marker has an irregular "Pac Man" shape and measures approximately 16 μm in diameter and 4 μm thick, or nearly half the size of a human hair. Irregularities around its circumference form a pattern that can carry data. The patterns may be read under a microscope or with pattern-recognition software in machine vision systems and sensors that link to a database for authentication. The technology also offers multiple levels of security because modified markers can detect physical, chemical, or biological threats to drug products (Invisible Security Marker, Adhesives Research, Inc., Glen Rock, PA, http://www.adhesivesresearch.com/ Burntside Partners, Inc., Ijams-ville, MD, http://www.burntsidepartners.com/ reader–database, Complete Inspection Systems, Inc., Indialantic, FL, http://www.completeinspectionsystems.com/.)