ODIN Prepares Scientific Pharmaceutical Benchmark

By Eric Van Osten

There’s clearly a momentum behind introducing more safety and security into the pharmaceutical supply chain. A safer, more secure supply chain leads to higher patient safety, which is desirable to the FDA, manufacturers, pharmacies, and patients.

One of the big issues has been how to efficiently enable an electronic pedigree process in the pharmaceutical industry without making it labor-intensive or paper-intensive, which would slow down the process and decrease efficiencies. In 2003, the FDA declared that RFID would be a good tool to enable pedigree (see “Catching Up with the FDA” on page 14). At the FDA Workshop in Bethesda, MD, in February, it was clear that many companies wanted the FDA to take a stand to develop the issue around pedigree, and create a national standard to resolve the issue of what tools to use for authentication, and promote RFID as the best option.

The question now is whether to use UHF or HF at the item level. There is no dispute that UHF will be the standard for the case and pallet level, based on the physics (read distance required and speed of reading tags). At the item level, the requirements are different, particularly in the pharmaceutical supply chain.

ODIN and Unisys Take Analytical Approach

ODIN technologies Inc. (www.odintechnologies.com) and Unisys (www.unisys.com) decided a more thorough study of this issue was necessary. Unisys and ODIN’s intent from the start was to conduct a scientific analysis of whether UHF or HF RFID is most appropriate for item-level pharmaceutical “use cases.” Bret Kinsella, Chief Operating Officer, and Chris Fennig, Director of Professional Services, share some of their findings here.

There are several important use cases based on the numerous critical points in a pharmaceutical packaging line, such as the point where the label is applied and when it is encoded. There’s the concept of verification, and in a pharma verified environment, the line must verify that the label is correct and that the RFID tag is functioning. Then there’s the process of association or aggregation between item level and cases or pallets, and the data must be available further down the supply chain for processing. Finally, there’s the concept of tracking at different points and authentication throughout the supply chain, as well as exception process.

ODIN and Unisys wanted to find out what might be hardest for RFID in general, and would HF or UHF be more appropriate in various use cases given the state of the technology today. ODIN talked to a lot of pharmaceutical companies to find out what was important to them. It worked with companies who have technologies and test artifacts that are relevant to this study, to get a lot of people who have technology or know-how to provide input into the test protocol.

Diagrams of RF fields using either UHF or HF tags (the reader is in the middle) in different use cases. The green represents what can be read. The graph at right should be used as a key to measure values in the charts above, with the numbers on the perimeter marking angle degrees, and the other numbers representing read rate percentages.
Click here for larger image.

Types of Tests Conducted

ODIN developed a two-phased approach to answering this question of UHF or HF at the item level. The first phase was dedicated to understanding the physics and scientific drivers of HF and UHF technology. Some critical metrics had not been quantified and made widely available in the past, such as a technical analysis of orientation sensitivity and maximum encode speed.

The second phase was to leverage what they learned about the physics and execute use case testing, specifically three use cases. The first focused on in-line verification of individual units on a conveyor line, and verification of tag functionality. ODIN conducted this testing on a conveyor, similar to a real pharmaceutical manufacturing plant.

The second use case was dedicated to understanding unit-to-case aggregation. At the unit level, the focus is really identifying the technology that can capture tags that are applied to different material types, and not so much about large populations being able to traverse a large number of tags, whereas at the case level ODIN tested case quantities of 24 and 48 units. That is a much different scenario because there are two issues: first, many tags in the field must be singulated (a reader can only talk to one tag at a time); and secondly, penetration through the material must occur to effectively capture the tags that are inside the case.

The final use case was focused on pallet-level penetration; quantifying the impact that HF and UHF unit tags have on UHF case tag readability when stacked on a pallet. The goal here was to penetrate the middle of a partial pallet effectively, and make sure that the reader can capture all the case tags that are present. As it turns out, each of the two available frequencies, HF and UHF, have associated tradeoffs that need to be considered. ODIN formulated opinions regarding the most important tradeoffs and how to mitigate the risk associated with committing to one of the two technologies.

What ODIN Learned From the Tests

ODIN confirmed that HF’s superior performance with liquids and blister packs make it a better solution for the pharmaceutical industry. ODIN learned that HF is much less material dependent than UHF. The wavelengths of HF signal (about 75 ft.) compared to UHF (about one foot) make liquids more easy to penetrate with HF RFID. Whereas HF tags cannot be encoded as quickly or read at a long distance, HF power is able to penetrate cases of unit containers to capture inner tags, which is critical for unit-to-case aggregation. Longer read range is important when reading cases and pallets and therefore UHF will continue to be the frequency of choice beyond the item level. However, when it comes to reading at the unit level, read ranges are short and controllable and there is no reason to go after long-range solutions at the unit level.

The sensitivity and orientation of the technologies also played an important role in the results. HF is much less sensitive to tag orientation, assuming you are able to move past an antenna to its full extent. Also, because HF technology is more mature than UHF, the quality of the tags is significantly more consistent. Another benefit to HF is that 13.56 MHz is a globally accepted standard, unlike the UHF range used in the U.S., which cannot be used in certain parts of the world.

The bottom line is that, for several reasons based on the physics of RFID, the technology today suggests that the best move for the pharmaceutical industry is to work with HF at the item level and continue to use UHF at the case and pallet level. Ultimately, with such large volumes of items in the field, it is essential to have high consistency with read rates the first, time because a lot of exception processing will deteriorate quickly into handling every bottle manually. HF RFID can ensure high read-rate performance and deliver better drug safety throughout the pharmaceutical supply chain.