Georgia Tech engineers have created a pill that could effectively deliver insulin and other injectable drugs, making medicines for chronic illnesses easier for patients to take, less invasive, and potentially less expensive.

Along with insulin, it also could be used for semaglutide — the popular GLP-1 medication sold as Ozempic and Wegovy — and a host of other top-selling protein-based medications like antibodies and growth hormone that are part of a $400 billion market.

These drugs usually have to be injected because they can’t overcome the protective barriers of the gastrointestinal tract. Georgia Tech’s new capsule uses a small pressurized “explosion” to shoot medicine past those barriers in the small intestine and into the bloodstream.

The pill relies on a tried-and-true bubbling reaction of water and sodium bicarbonate to build pressure inside the capsule after it is swallowed. Eventually the pressure overwhelms a small weak spot in the pill’s gelatin exterior, resulting in a jet of drug particles. 

The high velocity of the “explosion” sweeps away the mucus that lines the intestine much like a burst of air might shove water aside. It puts the drug right next to the epithelial cells that can transfer it to the bloodstream. Because the drug particles are moving so fast, protein-eating enzymes don’t have a chance to break them down.

The capsule itself is made of the same gelatin material as pills already in your medicine cabinet. It’s been strengthened by exposure to ultraviolet light to help it stand up to the extreme environment in the stomach and small intestine. The capsule has a small internal compartment containing the drug and positioning it for efficient ejection.

“Right from the start, we set an objective to develop the capsule so it can plug right into conventional capsule manufacturing methods,” said Joshua Palacios, the study’s first author and a former Ph.D. student in Prausnitz’s lab. “Obviously, we’re doing a few things differently, but it’s critical to make these capsules at low cost and in large quantity. Leveraging existing manufacturing processes is key to making broad impact with this technology.”

So far, no oral delivery methods for insulin are available to patients. While there are a few other protein drugs taken by mouth, most aren’t absorbed well in the intestine. For example, the body takes up less than 1% of the oral form of semaglutide, called Rybelsus; the other 99% is wasted. The insulin-carrying capsule Prausnitz and his team have developed is designed to increase that absorption, requiring less drug and increasing its effectiveness.

Now the team is working to further increase the percentage of drug that’s absorbed and exploring other injected drugs beyond insulin that might work in their capsule, such as semaglutide.

Prausnitz is known for pioneering microneedles for drug delivery through the skin. His work on skin delivery inspired the self-pressurizing capsule.

“I was thinking about all the different ways that we deliver medications across the skin and how this could be applicable in the intestine,” he said. “While there are mechanical, electrical, ultrasonic, laser, and other devices you can apply to the skin, they are too complicated to be swallowed. But jet injection, which has been widely used for needle-free vaccination, could work in the gut. It’s like a tiny bullet that shoots drug into tissue.

“In the end, there are some differences in the science and mechanism, but the thought process is the same: You shoot something at high pressure against your target.”