A better pill to swallow: Nanofiber film delivers ultrafast pain relief

Children and seniors who have difficulty chewing and swallowing conventional tablets may have an easier way to find pain relief. Cornell researchers have developed an ultrafast-dissolving nanofiber film that can deliver a cocktail of three drugs so quickly and effectively, 90% of the formulation is released in less than two seconds.

The findings were reported July 21 in the International Journal of Pharmaceutics. The project was led by Tamer Uyar, associate professor of fiber science in human centered design in the College of Human Ecology; the lead author is former postdoctoral researcher Asli Celebioglu.

As a fiber scientist, Uyar's work spans textiles, filtration, food packaging, agriculture and healthcare. That wide range is due to the outsize utility of nanofibers, which are 1,000 times smaller than a single human hair and therefore have an enormous surface area, allowing them to interact more easily with their surroundings.

When it came to selecting the right kind of nanofiber, the researchers skipped the obvious options favored by the pharmaceutical industry - such as edible polymers - and opted instead for cyclodextrin (hydroxypropyl-β cyclodextrin), a cyclic oligosaccharide that is produced from starch.

Uyar's lab previously developed a cyclodextrin-based fibrous membrane that removed approximately 90% of the microplastic triclosan from water.

"There are many drug formulations, but they typically are not water soluble," Uyar said. "But the fiber matrix of cyclodextrin helps increase water solubility of the drugs, and it increases their bioavailability, and masking the bad taste of the drugs as well."

The nanofiber film is produced through a process called electrospinning, by which an electric field draws ultrathin fibers from a liquid, in this case water. Because the process is commercially available, the approach is highly scalable.

"People usually use organic solvents to dissolve and process these drugs. But in our case, we only use water in this system, with the cyclodextrin and the drug itself," Uyar said. "So it's a very clean and green process."

Initially the researchers were focused on a single-drug formulation, but they soon embraced the challenge of incorporating three: acetylsalicylic acid (aspirin), paracetamol and caffeine. That combination of drugs, and their respective ratios, match that of the commercial painkiller Excedrin, commonly used to treat headaches and migraines. But first, Celebioglu and doctoral student Mahmoud Aboelkheir, a co-author on the paper, worked to understand the complexation and interactions between the three drugs and cyclodextrin.

The subsequent film, which resembles a breath strip, is the first nanofiber system that can release a triple-drug combination. To test it, the researchers developed a powder formulation as a control. While the nanofiber film dissolved and released 90% of the formulation in less than two seconds, the powder version released only 30%.

"That was very surprising. We were not expecting that ultrafast dissolving plus the high release of the drug in a very short time compared to the powder form," Uyar said. "And if you think about making a tablet, the tablet is going to take much, much longer."

Not only will the nanofiber film benefit people who have difficulty ingesting tablets, it will deliver superior pain relief for anyone taking the medication, according to Uyar.

"This proof of concept opens the way for us to use dual drug, triple drugs, or more," Uyar said. "We can further work on other formulations, as well."

The researchers made use of the Cornell Center for Materials Research; the Cornell NMR Facility, which is supported in part by the National Science Foundation; and the Department of Human Centered Design facilities.