Mass spectrometry separates fake from genuine packaging

Researchers at UK laboratory standards company LGC say they have demonstrated the feasibility of using advanced mass spectrometry techniques to identify counterfeit pharmaceutical packaging by measuring variations in stable isotope levels.

Using the technique, the company's researchers look at the ratios of calcium and lead isotopes in cardboard packaging and printing ink used in drug cartons and containers and distinguish the origin of packaging materials.

"All naturally occurring elements consist of one or more stable isotopes and the isotopic profile of elements can reveal subtle variations depending on the source of origin," according to the scientists.

The information gleaned from the testing can not only distinguish genuine from fake packaging and help prevent fake medicines from reaching patients, but potentially provide admissible evidence against drug counterfeiters for subsequent prosecutions, they say.

The technique was developed by the LGC in collaboration with colleagues at pharmaceutical company GlaxoSmithKline in a project funded by the UK National Measurement System.

LGC scientists used a laser ablation system coupled to a multi-collector inductively coupled plasma mass spectrometer (LA-MC-ICP-MS) to measure and compare calcium and lead isotope ratios in nine pharmaceutical packaging samples.

The results of the LGC study showed that, of the nine samples analysed, the five authentic samples displayed different calcium isotope ratios to those of the counterfeit samples.

And when analysed and plotted, the calcium ratios of two fake samples known to originate from the same country formed a cluster.

Interestingly, the two other counterfeit samples, which were known to originate from different countries, also had similar calcium isotope ratios to the first two counterfeit samples analysed, while ratio analysis of lead isotopes showed similar clustering.

LGC is looking at using the same ratio technique for sulphur isotopes as a way to identify counterfeit pharmaceuticals.

The research is published in the July edition of the journal Rapid Communications in Mass Spectrometry (2010; 24: 1993-1999).