NIR spectroscopy to predict pill quality

Laura S. Marshall, laura.marshall@photonics.com

The quality-testing process for pharmaceuticals raises drug costs, according to pharmacy professor Stephen Hoag, but he says that evaluation with near-infrared spectroscopy could help lower those costs.

“The drug industry used to test a pill for dissolution, then send a sample for analysis to a wet lab,” said Hoag, who works at the University of Maryland School of Pharmacy. “Now – with near-infrared high-speed computers and software – you can get information in real time. So instead of evaluating each step and waiting three days for samples to come back, [testing] is instant.

“It impacts inventory, materials and space for storage, and shortens the manufacturing time – all things that have financial implications. And you know industry is under a lot of pressure to cut costs in health care.”

Hoag and his team found in 2008 that the technology worked for testing of coated tablets, and now they have demonstrated the use of NIR to predict the dissolution rate of a pill – specifically, a matrix-type controlled-release tablet that releases medication from the inside. With this kind of tablet, the process is controlled by physical polymers that slow it down. The new study was published in the International Journal of Pharmaceutics in December 2009.

Hoag reported that the technology predicted accurately the dissolution rate of the drug thiophylline in matrix pill form and added that this gives an indication of how quickly it would dissolve in the human body.

“This may be a very narrow topic, but I think it will someday have huge implications for pharmacy, as [NIR] can also do ID testing,” he said. “That is, it would relieve pharmacists of the need to routinely inspect every prescription.”

NIR is already commonly used in quality measurements in crop production, forage, fruits, food processing baking products, timber, meats and nonfood agriculture. The pharmaceutical industry began to use it in the 1990s because it responds to both chemical and physical properties of a given substance.

Drug regulators also could use the NIR technique to determine the ingredients in pills. “For identification testing,” Hoag said, “anytime you bring in a material in the drugmaking process, the FDA wants real data proving that the material really is that material.”

He added that the new technology possibly could avert disasters with consumer drugs, such as the 2006 tainting of cough medications that killed more than 40 people in Panama and 80 children in Haiti.

Hoag believes that the cost savings associated with NIR testing could trickle down to the patient, as a slightly reduced production expense could be increasingly significant for companies as they produce more complex biology-based therapies.

The “fundamental change” Hoag expects the technique to afford the pharmaceutical industry may not come tomorrow, he said. “We still have a long way to go before you have this complete system where [pills] flow in one side and information flows out the other side.” But he emphasized that his team’s experiments could lead to lower expenditures for drugmakers and more consistency in the quality of pills.