Scientists use NIR to predict how quickly pills dissolve in body

Jan 7 2010

Scientists at the University of Maryland, Baltimore have successfully used near-infrared spectroscopy (NIR) -- a method already used to test farm product quality -- to predict how quickly pills dissolve in the body. The experiments could lead to cost savings for drug makers and more consistency in the quality of pills, says Stephen Hoag, PhD, professor, University of Maryland School of Pharmacy.

In a study published last month in the International Journal of Pharmaceutics, Hoag and his colleagues used NIR to accurately predict the dissolution rate of a matrix-type controlled release tablet. Matrix tablets release their medication from the inside controlled by physical polymers that slow the process.

In 2008, the team successfully tested NIR technology on coated tablets that release slowly because of compounds in the coating. The team develops systematic methods for formulating controlled and immediate release tablets.

"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, that is, it would relieve pharmacists of the need to routinely inspect every prescription," says Hoag.

Using NIR for identifying ingredients in pills will also help regulators. "For identification testing, anytime you bring in a material in the drug making process, the FDA wants real data proving that the material really is that material." He said it may be possible to use the new technology to avert consumer disasters such as the tainting of cough medications in 2006. More than 40 people died in Panama from ingesting a lethal combination of a sweetener used in many cough medicines with an antifreeze chemical and 80 children died in Haiti because of the same combination in cough syrup.

NIR technology measures properties of materials using part of the infrared portion of the light spectrum. It has widespread use in quality measurements in crop production, forage, fruits, food processing baking products, timber, meats, and non-food agriculture.

In the 1990s, it began to show up in the pharmaceutical industry. The technology is especially useful in analyzing pills because it responds to both chemical and physical properties.

Hoag said the technology accurately predicted how quickly matrix pills of the drug thiophylline dissolve, which gives an indication of its dissolution rate in the human body.

"This is a fundamental change because the drug industry used to test a pill for dissolution, then send a sample for analysis to a wet lab," says Hoag. "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, it is instant. It impacts inventory, materials, 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."

He said in the competitive pharmaceutical industry, cost savings with NIR identification would trickle down to the patient. Although the profit margin on the average pharmaceutical is often very high, a small cost savings in production with NIR testing may make more and more of a difference to companies as they produce more complex biologics, or biology-based, therapies.

"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.