Roche scientists use chemometrics in fake medicines fight

Raman spectroscopy has become a key front-line tool to distinguish genuine medicines from counterfeits, but scientists at Roche have been combining this with additional chemical profiling or chemometrics stages to provide additional information that can be used to help guide investigations and enforcement.

Scientists from the drugmaker and the University of Lausanne in Switzerland looked at the use of Raman spectroscopy as a screening tool to identify suspect products as genuine or counterfeit, followed by the application of chemometrics to classify fakes on measures such as principal component analysis (PCA).

The team have developed a workflow to guide the investigative process, for example classifying counterfeits depending on whether they are from an existing or new counterfeit class.

"If the new counterfeit falls into an existing class, no further analyses are consequently required to determine its chemical composition," write the authors in Analytica Chimica Acta (705 (2011) 334– 341). However, "if a new class of counterfeits is created, its chemical content is established with support techniques such as Raman spectral interpretation, GC–MS and infrared spectroscopy."

The result is an ever-growing, "living database" which can become a powerful tool for investigations, something which would not have been possible using conventional classification tecniques.

A sampling study designed to calibrate the technique identified 27 counterfeits separated into 15 chemical classes. Interestingly, different seizures could be linked according to chemical profiling, which could provide "strategic and operational intelligence" which could be used for preventive measures and to provide investigative services with investigational leads.