Scientists from Purdue University have created a device that can quickly determine if new pharmaceuticals have trace crystallinity, which affects the amount of the drug that can enter the body. This new instrument can detect this crystalline content in the early stages of drug formulation. It works by measuring the amount of light emitted when the drug powder is crushed.
"Any light that is measured is directly proportional to how much crystallinity is in the formulation," said Casey Smith, a graduate student in Purdue's Department of Chemistry and co-lead study author. Drugs that do not dissolve quickly means that the drug can travel through the body before the drug is able to have the desired effect. One way to get around this issue is to cast a drug in a polymer matrix that is easily dissolvable.
Says Garth Simpson, a Purdue University Chemistry professor, “New drugs that are coming out are increasingly larger and more hydrophobic, or do not dissolve easily in water. If crystallinity is detected, there's a good chance that it won't dissolve in a time frame required to be bioavailable and efficacious."
The new instrument, which can detect crystallinity in levels as low as 140 parts per million was created in collaboration with the Department of Chemistry's Jonathan Amy Instrumentation Facility. The device uses a solenoid to strike powder that is on a microscope slide. Under the slide lies a photomultiplier tube, which measures the optical radiation resulting from the triboluminescence of the powder. A motor moves the slide down the line to probe new areas of the powder.
"This technique would be more like a prescreen off an assembly line in a factory where they're making these drugs. They can send a small amount of the material into this instrument for triboluminescence measurements. If they get a positive outcome from the sample, then they can send it off for more rigorous testing," said Scott Griffin, the co-lead study author.
The journal is written by students in Dr. Simpson’s laboratory, in conjunction with researchers from Merck & Co., and is published in the journal, Analytical Chemistry.