In the developing world, about 10 percent of medications are actually inferior counterfeits of the real thing. Unfortunately, these same regions often lack the equipment needed for detecting those fakes. An inexpensive new system, however, could remedy that problem.

Developed by a team at the University of California-Riverside, the setup requires users to start by placing a liquid pharmaceutical sample on a glass slide, where the liquid is drawn into a series of parallel microfluidic channels. One end of that slide is then placed in liquid nitrogen, creating a temperature gradient along the length of the slide.

A simple USB camera shoots video of the procedure. It records the manner in which the sample freezes, separates into different components, or otherwise reacts to the temperature-change over time (and based on distance from the nitrogen). Bitmap stills are then created from that video. Those stills are known as "chronoprints."

Utilizing freely-available software created by the researchers, a user can then compare the chronoprints of a sample to those of the genuine medication that the sample is claimed to be. If it's a counterfeit, it will have reacted differently to the change in temperature, so its chronoprints won't match those of the real thing. The program will alert the user to that fact.

The technology could also be used on solid medications dissolved in water, or even on food. In fact, in lab tests, it was successfully used to differentiate between authentic and adulterated olive oil.

"By basically converting a chemical sample to an image, we can take advantage of all the different image analysis algorithms that computer scientists have developed," says lead scientist Asst. Prof. William Grover. "And as those algorithms get better, our ability to chemically identify a sample should get better, too."

A paper on the research was recently published in the journal ACS Central Science.

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