Drug counterfeiting, which was once limited to under-developed nations, has recently made its way to the U.S., Europe, and Japan. The number of counterfeit-drug cases tracked by the FDA, for example, grew from five in 1998 to 58 in 2004. To protect patients from this growing threat, drug companies are making wider use of secondary seals on drug vials and planning to use radio frequency identification (RFID) tags as the technology evolves.

“A secondary seal refers to the closure system that does not come into direct contact with the drug,” says Carol Mooney at West Pharmaceutical Services in Lionville, Pa. (westpharma.com). “It consists of an aluminum seal crimped over the vial and stopper and is topped with a plastic Flip-Off button. Secondary seals are used for drug protection and to give manufacturers space for usage information.” Ultimately, she adds, RFID tags containing track-and-trace information will provide a more significant barrier to counterfeiters.

An example of drug resistant packaging comes from PSGA, a manufacturer of the anemia drug Procrit. Its custom-designed package uses color coding and covert printing to help fight counterfeiting. Seal colors and plastic Flip-Off buttons match colors on the label to help identify the drug as genuine. Printing on the button identifies contents as a single or multidose drug. Printing on the seal shows the brand name and dosage strength. The printing remains hidden until a user removes the plastic button.

Another example comes from drug manufacturer Amgen. It uses a custom button as an anti-counterfeiting measure for the drug Epogen. “Its buttons are molded with the Epogen logo, along with dosing and strength information. Amgen uses different colored seals to differentiate single from multi-doses of the drug,” says Mooney.

Pfizer recently introduced a printed plastic button for vials of Diflucan, a drug that was counterfeited in Japan. “The printing includes Japanese characters and the strength of the medication. Specialized printing and color-coded overseals also differentiate drugs that can be confused with others having similar names,” add Mooney.

RFID tags will let manufacturers track-and-trace drugs through their supply chain. RFID tags have been cited for their potential in a 2004 FDA report, Counterfeit Drug Taskforce. According to the report, says Mooney, reliable RFID technology will make copying medications either extremely difficult or unprofitable. The report also recommends that pharmaceutical manufacturers use some form of RFID by 2007 because authentication data embedded in an RFID tag cannot be altered. Thus, the tags would provide more security than paper documents accompanying the drug. Documents are relatively easy to alter or forge.

Molding a tag into the plastic button rather than placing it within the label also overcomes a problem inherent in RFID label technology. Tags close to liquids are more difficult to read because liquids interfere with signals transmitted by the tag.

“Other item-level technologies for thwarting drug counterfeiting include spectroscopic inks and the application of high-quality, full-color graphics,” says Mooney. “Information in bar codes, for example, can be printed on buttons in colored inks that are readable only under special lighting. And bar coding is read only with a scanner. High-quality graphics help identify and authenticate drugs as genuine. The sophistication of printing and molding make this technology difficult for drug counterfeiters to duplicate.”

Douglas Stockdale of Stockdale Associates Inc. also contributed to this article.