Purdue University’s edible “security tag” in medical drugs combats pandemic counterfeiting rise

05 Jul 2022 --- Researchers at Purdue University, US, are developing an edible “security tag” embedded into medicine to expose counterfeiters. The tag acts as a digital fingerprint for each drug capsule or tablet, using an authentication technique called “physical unclonable functions” – or PUF – which was originally developed for information and hardware security. 

PackagingInsights speaks to Young Kim, associate professor at Purdue University’s Weldon School of Biomedical Engineering, about the need for security tags for the pharmaceutical market. 

“The need for advanced authentication and anticounterfeit technologies for pharmaceutical products is ever-growing as the practices of medication counterfeiting become increasingly advanced during the COVID-19 pandemic,” says Kim. 

Using this new solution, counterfeiters would have to uncrack a complicated puzzle of patterns not fully visible to the naked eye to imitate a drug.

Unduplicatable patterns
PUFs can generate a different response each time they are stimulated, rendering them unpredictable and extremely difficult to duplicate. Even the manufacturer wouldn’t be able to recreate an identical PUF tag.

Kim’s group is the first to create an edible PUF – a thin, transparent film made of silk proteins and fluorescent proteins genetically fused together. Since the tag is easily digestible and made entirely of proteins, it can be consumed as part of a pill or tablet.

Shining various LED light sources on the tag excites the fluorescent silk microparticles, causing them to generate a different random pattern each time. The microparticles emit cyan, green, yellow or red fluorescent colors.The researchers have created a silk film “security tag” to go on the surface of drug capsules. The photo was taken with a green filter for visibility. 

Digital bits can then be extracted from an image of those patterns to produce a security key, which a pharmacy or patient would use to confirm that a drug is authentic.

The researchers are currently converting this process to a smartphone app for pharmacies and consumers.

The liquid medicine challenge
Kim explains that one of the most challenging applications when developing cyber physical security technologies for pharmaceutics is liquid medicines. 

“We got an idea of using silk proteins. Interestingly, silk proteins crystalize very well. The crystallinity can be maintained for a long period of time.”

“Our method of using silk proteins to encode information paves the way for realizing anticounterfeit measures and authentication features at the dosage level for liquid dosage forms.”

Protecting human health
Meanwhile, the most vulnerable goods for counterfeiting are pharmaceutical products and high-value alcoholic spirits. 

“One out of five adults in the UK experienced purchasing counterfeit alcoholic spirits, in particular whiskies and gins,” notes Kim. “The current global whiskey market is estimated to be US$60 billion. Fake alcoholic spirits are one of the most troublesome counterfeit products that affect human health.”

“The main applications include pharmaceutical products, medicines, and high-value goods such as alcoholic spirits. Our security technologies can potentially be used for other security and cryptographic applications that require obliteration immediately after being scanned.”

In related news, Australian technologist eBottli is exploring connective packaging’s potential for anti-counterfeiting in the wine industry with a suite of tracking and blockchain data technologies, geolocating services and unique identifier labels.From left to right: Researchers Jung Woo Leem and Young L. Kim.

Fake medication 
Fake medicine is a thriving business, making up at least 10% of global pharmaceutical commerce while claiming thousands of lives each year, according to the researchers.

In the US, counterfeit drugs range from cancer and diabetes treatment to erectile dysfunction medication. Counterfeit opioids have caused deaths in 46 states.

However, tagging drugs can guard them against fakery and help pharmacies better verify the legitimacy of a drug before selling to consumers.

“We believe that we need more scientists and researchers to work effectively at the intersection of academia, pharmaceutical companies, and government agencies. We were also hoping that our papers will bring more attention to the community and funding agencies to be aware of this imperative healthcare sustainability problem.”

“Definitely, we will need industrial collaborations and partnerships to scale up. We are currently forming a startup company spun out from Purdue University,” concludes Kim. 

By Natalie Schwertheim