Spectroscopy sees through packaging to thwart drug fakers

UK based researchers have added another dimension to anti-counterfeiting with an alternative Raman imaging method that is powerful enough to detect fake drugs without opening the package.

The researchers, at CCLRC Rutherford Appleton Laboratory, said the imaging technology is at the early stages of development but that they plan to have a marketable instrument within a year or so. The CCLRC has teamed up with several pharmaceutical companies to establish the instrument's potential and limitations, in applications such as pharmaceutical quality control.

The technology uses spatially offset Raman spectroscopy (SORS), which reads Raman scatter laterally away from the laser point. This serves to suppress fluorescence signals that stem from packaging, capsule shells or tablet coating, which can interfere with the weaker subsurface Raman signals of a products active pharmaceutical ingredients and excipients.

The growing counterfeit drug market is estimated to be worth $75bn (€57.3bn) globally by 2010, an increase of 90 per cent from 2005. Although counterfeiters often find a way around existing strategies such as on-pack technologies, limiting their effectiveness, SORS has the potential to give them a tough fight, according to the researchers.

"They would have to supply the correct composition of the tablet to get around the technique," Pavel Matousek, team leader, told In-PharmaTechnologist.com.

"Although this would still represent the infringement of pharmaceutical patents, the key point is that the drug would not pose the same health hazard to the patient as do the counterfeit drugs with incorrect active ingredients or with active ingredients at improper concentration."

The scientists claim that SORS possesses higher chemical specificity than near infrared (NIR) spectroscopy and that its technology has potential to replace NIR in those applications.

"The method [SORS] is based on conventional Raman spectroscopy technique, where the Raman effect occurs when light bounces off molecules and its colour changes very slightly. This change gives a unique fingerprint of the chemical," said Matousek.

The CCLRC plans to develop a portable instrument but claims its technology implements easily on conventional hand-held Raman instruments already on the market. In addition, they are to launch a spin out company - LiteThru - later this year, which plans to take this technology further. But, they are still interested in licensing out the technology to instrument manufacturers.