New Isotope Fingerprinting Technique Flags Counterfeit Medicines by Factory Origin

New Isotope Fingerprinting Technique Flags Counterfeit Medicines by Factory Origin

(IN BRIEF) A collaborative study by the University of Copenhagen and Stanford University has revealed that pharmaceuticals possess unique isotopic signatures—based on stable isotopes of carbon, hydrogen and oxygen—that correspond to their manufacturing conditions. By profiling these δ²H, δ¹³C and δ¹⁸O ratios in ibuprofen and its excipients, researchers can trace a drug’s precise factory of origin and identify counterfeit or stolen batches. With counterfeit drugs on the rise in the EU, this approach offers a rapid (50 samples in 24 hours), reliable method for regulators and manufacturers to authenticate products. Ongoing work aims to validate the technique against real-world counterfeit samples, potentially transforming anti-counterfeiting measures in the pharmaceutical industry.

(PRESS RELEASE) COPENHAGEN, 7-Aug-2025 — /EuropaWire/ — Researchers from the University of Copenhagen and Stanford University have discovered that every pharmaceutical product carries a distinct isotopic signature, enabling pinpoint tracing of its origin and detection of counterfeit or diverted drugs. Their recent study, focusing on ibuprofen, demonstrates that variations in stable isotopes of carbon, hydrogen and oxygen—introduced during synthesis or via plant-derived excipients—form a molecular “fingerprint” unique to each manufacturing site. This method could revolutionize efforts to combat the growing scourge of pharmaceutical crime, which saw EU authorities seize over 426,000 illicit medicine packages worth €11.1 million in a single eight-month operation in 2024.

“Because isotope ratios remain constant over geological timescales, they provide an unforgeable marker of where and how a substance was produced,” explains Postdoc Else Holmfred of the Department of Pharmacy at the University of Copenhagen and Stanford University. “If stolen or substandard batches are repackaged for illicit sale, we can now chemically verify their provenance—and prove they’ve been tampered with.”

The team analyzed approved ibuprofen formulations alongside common excipients like corn starch and cellulose, showing that each sample’s δ²H, δ¹³C and δ¹⁸O values vary subtly according to factors such as geographic origin, water source and photosynthetic pathway. “These isotopic patterns are impossible to replicate artificially, making them a powerful tool against counterfeiting,” notes co-author Associate Professor Stefan Stürup.

Looking ahead, Holmfred is conducting follow-up research to confirm the technique’s ability to distinguish actual counterfeit medicines from authentic products. Preliminary data already reveal significant isotopic discrepancies in illicit samples that appear identical to genuine tablets. Importantly, executing such analyses requires only standard isotope-ratio mass spectrometry equipment and can process around 50 samples in 24 hours.

Read the study “Revealing the Stable δ2H, δ13C, and δ18O Isotopic Patterns of Ibuprofen Drug Products and Commonly Used Pharmaceutical Excipients.”

Media Contacts:

Postdoc Else Holmfred
Department of Pharmacy
Email: else.holmfred@sund.ku.dk, holmfred@stanford.edu
Mobile: +1 650 507 9203

Associate Professor Stefan Stürup
Department of Pharmacy
Email: stefan.sturup@sund.ku.dk
Phone: +45 35 33 62 84

Communications Officer Anna Ahlbom
UCPH Communication
Email: anna.ahlbom@adm.ku.dk
Mobile: +45 93 56 50 26

Communications Adviser William Brøns Petersen
UCPH Communication
Email: william.petersen@adm.ku.dk
Mobile: +45 93 56 55 80

SOURCE: University of Copenhagen