August 2010

Fighting the counterfeit drug war – LGC detects fake packaging using mass spectrometry

LGC, the UK’s designated National Measurement Institute for chemical and bioanalytical measurement, is using high accuracy mass spectrometry (MS) for the first time to measure variations of calcium (Ca) and lead (Pb) isotope ratios in order to identify counterfeit pharmaceutical packaging. By applying this technique to look at Ca and Pb isotope ratios in the cardboard packaging and printing ink used in drug cartons and containers, scientists can now potentially distinguish the source of origin of packaging materials, thus providing valuable evidence against drug counterfeiters for subsequent prosecutions.

Detecting counterfeit drugs and packaging has traditionally relied on a combination of visual examination and chemical analysis of the goods and packaging. However, as counterfeiting techniques are becoming increasingly sophisticated, more sensitive detection methods are required. Many counterfeit pharmaceuticals now contain the same active pharmaceutical ingredient as the genuine product, so their elemental composition is often very similar, if not identical to that of the real drug. In addition, both genuine manufacturers and counterfeiters often combine a number of elements of packaging materials sourced from different suppliers, thus making it difficult to identify counterfeits that have been seized in different locations.

To develop methods to help identify counterfeit pharmaceutical packaging, LGC scientists have worked on a research project in collaboration with GlaxoSmithKline and funded by the UK National Measurement System. 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. Advances in mass spectrometry have made possible the detection of these variations.

Described in a recently published primary paper*,  LGC scientists used a laser ablation system coupled to a multicollector inductively coupled plasma mass spectrometer (LA-MC-ICP-MS) to measure and compare Ca and Pb isotope ratios of nine pharmaceutical packaging samples.

As Ca is used in the cardboard/papermaking process and Pb is a major component of ink, both elements are expected to be present in packaging (cardboard/ink) at relatively high concentrations. The results of the LGC study showed that, of the nine samples analysed, the five authentic samples displayed different Ca isotope ratios to those of the counterfeit samples. When analysed and plotted, the Ca isotope ratios of two counterfeit samples known to come from the same country clustered together. Two further counterfeit samples, from different countries, also had similar Ca isotope ratios to the first two counterfeit samples analysed. Isotope ratio analysis of Pb showed similar clustering of results.

LGC’s Dr Ruth Hearn, Team Leader in Chemical Measurement and Calibration said: “Working in collaboration with GlaxoSmithKline was vital to the success of this project because it enabled LGC to gain first-hand insight to the problems faced by pharmaceutical companies in tackling drug counterfeiting. This successful collaboration has enabled LGC to demonstrate the technique’s potential to be used by the global pharmaceutical industry as a tool for the identification of counterfeit drugs.”

LGC is also using the same technique to provide high accuracy sulfur isotope ratio measurements to identify counterfeit pharmaceutical drugs.

* Application of laser ablation multicollector inductively coupled plasma mass spectrometry for the measurement of calcium and lead isotope ratios in packaging for discriminatory purposes, Rebeca Santamaria-Fernandez and Jean-Claude Wolff

Rapid Commun. Mass Spectrom. 2010; 24: 1993–1999