New Method to Test Water Content in Drugs May Allow for Less Costly Manufacturing

Researchers have created a new method to quantify water content in solid pharmaceutical drugs that is quicker, and more accurate than the FDA-accepted method used worldwide.

Testing drugs for water content is required by the FDA and is a costly part of manufacturing drugs.

“Every therapeutic drug has a narrow range of optimal water content, which needs to be controlled to avoid potential adverse effects on patients,” said lead researcher Daniel Armstrong, PhD. “In addition to other advantages like speed and lower costs, our new system can also be automated, reducing labor costs for manufacturers with potential economic benefits for consumers.”

In a study published by the Journal of Pharmaceutical Sciences, researchers used a headspace gas chromatography analytical method with ionic liquid tubular capillary gas chromatographic columns. To detect water content, they used the Shimadzu Scientific Instruments Tracera GC-2010 Plus, since it is sensitive to water.

Headspace gas chromatography is the process of measuring chemical components as they diffuse to the top of the vial containing the sample. In the study, researchers used 1 ionic liquid as a solvent in the vial containing the sample, and used another to line the ionic liquid column.

Researchers compared their new method with the FDA-approved method of Karl Fischer titration that involves putting the sample in a vacuum oven to measure water content. Karl Fischer titration takes hours to achieve results, while the new method only took 10 minutes to complete.

The new method takes 5 minutes to heat the samples and 5 minutes of chromatographic run time, according to the study. Researchers also found that Karl Fischer titration was inaccurate in many common solid drugs tested.

This new method only requires a sample of 10 milligrams to complete the test. Being able to effectively use such a small amount of the drug can provide cost savings for manufacturers.

Researcher believe that their findings show that this new method is less costly, quicker, and more accurate than the standard method.