Raman spectroscopy for drug safety

In the summer of 2016, the US Drug Enforcement Administration (DEA) released the terrifying information that hundreds of thousands of counterfeit prescription pills had reached the US drug market, targeting the millions of nonmedical users of pain relievers.

What most of these drugs had in common was the deadly heroin additive, fentanyl, responsible for the overdose epidemic sweeping the US. But while alarming that traffickers of the powerful narcotic have expanded dealings to prescription drugs, fentanyl is just the tip of the global counterfeit iceberg.

From fake cancer drugs and tainted sex stimulants to not-so-natural herbal remedies and anti-malarial copies, the counterfeit industry knows no bounds. But as law enforcement grapples with the crisis, handheld Raman spectroscopy is providing a defense.

This spectroscopy technique interrogates the vibrational states of molecules by directing a laser light at the material. Inelastic scattered light is detected, providing a spectrum, or chemical fingerprint, of the molecules.

"Raman spectroscopy assigns specific chemical signatures to the ingredients present in a drug," says Sulaf Assi, a lecturer in forensics sciences from UK-based Bournemouth University. "Counterfeit drugs include branded as well as generic medicines, and in each case we're interested in the active pharmacological substances that will have very specific Raman signatures."

According to Assi, handheld Raman is easy to use, cheap to maintain, requires no sample preparation, and operates in all climate conditions. And while she describes the technology as "still being expensive and in its infancy," she highlights different configurations that are set to thwart the counterfeiters.

Igor Lednev, a professor at the University at Albany, State University of New York (USA) and colleagues are developing laser spectroscopy to interrogate traces of body fluids, hair, and gunshot residue.

"Within 10 years, Raman spectroscopy will be a universal tool to use at any crime scene," Lednev says. "When I started my career, I needed to spend all night in the laboratory to measure a single Raman spectrum, but now you can do this in a millisecond with a portable system."

In an article in the April 2017 issue of SPIE Professional, science and technology writer Rebecca Pool, describes how optical technologies help identify deadly counterfeit drugs.

Read the full article about Raman spectroscopy for drug safety in SPIE Professional.