May 8, 2007—To be ready for California’s upcoming pharmaceutical electronic pedigree (e-pedigree) requirement, Cardinal Health predicts it will have RFID technology up and running in its Sacramento, Calif., distribution center by summer’s end. The implementation will support both HF (13.56 MHz) and UHF (915 MHz) passive RFID tags—despite Cardinal Health’s determination that HF RFID does not work well in its operations.
The $74.9-billion-a-year company distributes one-third of all pharmaceutical, medical, lab and surgical products in the United States. Headquartered in Dublin, Ohio, the firm is installing both HF and UHF RFID interrogators in its operations so it can read the item-level serial numbers encoded in passive RFID tags on the individual bottles of drugs it receives from drug manufacturers. The serial numbers will then be used to update each item’s e-pedigree, a secure file that documents each move a product makes through the supply chain. Cardinal Health will use RFID to record when it receives a drug, as well as the date it ships that drug to a specific pharmaceutical retailer or other customer.
Although quite a few states have passed legislation calling for drug pedigrees that can be paper-based, California is the only one with a law requiring drug manufacturers, wholesalers and distributors to create e-pedigrees to track and trace all prescription drugs distributed within the state. Originally, California’s e-pedigree legislation was supposed to take effect in January 2007, but the law was pushed back two years and is now slated to go into operation in January 2009.
“For every item we receive, we have to receive a pedigree,” says Julie Kuhn, VP of operational technologies at Cardinal Health, “and for every item that is shipped out, there has to be a pedigree.” In addition to collecting RFID data for drugs it receives from manufacturers and distributes to customers, Cardinal Health will also use RFID interrogators to cull the serial numbers from any pharmaceuticals returned to its Sacramento distribution center. That data will be used in an e-pedigree to document the return. That e-pedigree, along with the drug, will then be sent back to the manufacturer.
The company has spent months testing RFID to track pallets and cases of drugs, as well as individual items, to better understand how tags are applied, encoded and read at normal production speeds (see Cardinal Health Readies Item-Level Pilot). Those tests have led Cardinal Health to conclude that EPC Gen 2 UHF tags are optimal for its operations (see Cardinal Health Deems RFID Pilot a Success).
During its tests, Cardinal Health achieved read rates as high as 99.9 percent when using EPC Gen 2 tags on individual items packed in cases and moving down a conveyor at 60 feet per minute. Cardinal Health’s conveyors typically run 120 feet per second, and even at that speed, the system successfully read the UHF Gen 2 tags more than 90 percent of the time.
Pfizer and other drug manufacturers are presently using HF tags (see Pfizer Using RFID to Fight Fake Viagra and Pfizer Prepares for Viagra E-Pedigree Trial). In Cardinal Health’s RFID tests, however, HF tags achieved read rates of only 60 to 80 percent (depending on the type of HF tag) on conveyors moving at 60 feet per minute, Kuhn says. The read rates for those tags dropped considerably when tested on conveyors moving at 120 feet per second.
The results are a clear indication to Cardinal Health that HF RFID is not currently ideal for high-volume distribution centers. “We are designing both HF and UHF into our processes,” Kuhn says, “but through the testing that we’ve done, and our pilot activities, we’ve clearly demonstrated that HF is not going to work. While HF may work well in a manufacturing application, it does not work well in a high-volume distribution environment like ours.”
To work around the low read rates—and there must be a work-around because to fully document a shipment using RFID, 100 percent of all items must be identified—Cardinal Health is creating an exception-handling line to divert cases containing item tags not successfully read to an area where those items can be manually accounted for.
Slowing down the conveyors to boost HF read rates is not an option, according to Kuhn, who says: “We can’t slow the lines down; we have to get our orders out.”
One possibility might be the use of inference, which would allow Cardinal Health to accept a trusted manufacturer’s shipping notices listing the items in each case, and to presuppose, for example, that a case expected to contain 72 items does indeed contain that quantity, even if not all items’ tags were read during that case’s interrogation. “What we’d like to do is be allowed to assume that we know what those missing units are, based on electronic communication from the trusted partner,” Kuhn says. “If the manufacturer has said we were supposed to receive 72 and we only read 68, can we assume that all 72 are in the case?”
The California legislation neither prohibits nor condones inference, so Cardinal Health is asking the industry to work together to determine whether or not inference can work. The company would also like to see the pharmaceutical supply chain industry settle on a standards-based way to document the drug’s movement in the supply chain, using a single tag frequency and air-interface protocol.
Still, the company is realistic. “I don’t know if we will ever see a unified approach, because everyone is trying to optimize the technology for their environment,” says Kuhn. “The challenge I lay out is for the [RFID] vendor community to find a way for both of these technologies—HF and UHF—to coexist, and to coexist effectively.”