Insulin Pill May Free Millions From Daily Injections

Medically Reviewed by Gary D. Vogin, MD
From the WebMD Archives

Aug. 26, 2001 -- A new way of delivering insulin by mouth may mean freedom from multiple daily injections for the millions of people with diabetes who depend on insulin to control their blood sugar.

Researchers from Purdue University in West Lafayette, Ind. have developed a plastic with a gel-like consistency that protects insulin until it reaches the small intestine -- where the blood can absorb it. Other ways of taking oral insulin have failed because the insulin is destroyed along the way by harsh acids in the stomach, report researchers Aaron C. Foss, a graduate student in chemical engineering, and Nicholas A. Peppas, ScD, a professor of chemical and biomedical engineering. Foss and Peppas presented their findings Sunday at the annual meeting of the American Chemical Society in Chicago.

By taking very small particles or spheres of a plastic-like material and infusing them with insulin, the researchers are able to create granules that are then encased in a shell and swallowed like a pill, Foss tells WebMD. Once in the small intestine, the plastic swells and releases the insulin into the bloodstream. The plastic also intercepts calcium, which would normally keep the pores of the small intestine tightly shut. By doing so, the insulin can more easily slip into the bloodstream, Foss says.

In studies conducted in animals, 16% of insulin delivered with the new material made it into the bloodstream -- a major improvement over the 0.01% that has been previously reported with oral insulin. Foss says that if further testing confirms these findings, he will seek FDA approval to begin testing on people within the next three or four years.

Diabetes occurs when the body does not produce or properly use insulin. Insulin is a hormone that is needed to regulate sugar and other nutrients in the blood. Nearly 16 million Americans suffer from diabetes and one of every 10 of those takes insulin on a daily basis, according to the American Diabetes Association.

"This pill may one day take the place of daily insulin injections," Foss says. "There is great promise in the ability to deliver insulin orally, but dosages are still up in the air."

Other researchers have also reported early successes in developing inhaled insulin that is rapidly released into the blood through the lungs.

"Inhaled insulin is further along in studies," Foss says. "With oral insulin, once you know what that set amount of insulin you need is, it's foreseeable that we would be able to administer the full dose through an oral route." As it stands, inhaled insulin must be coupled with injections.

Jeffrey Miller, MD, director of clinical endocrinology and diabetes at Thomas Jefferson University and Hospital in Philadelphia, says the major benefit of inhaled or oral insulin is that it could potentially eliminate the need for injections.

"When you mention the word insulin, everyone freezes up and says 'I can't inject myself,' and an alternative form to injection whether inhaler or pill will help get away from injections and improve compliance," he tells WebMD.

At least one prominent diabetes researcher is not so sure this new approach will work because it doesn't account for dosing variability or timing.

"Insulin is delivered in a more precise way than any other medication," says Richard Jackson, MD, a senior physician at the Joslin Diabetes Center in Boston. And timing is crucial because it has to match the food you consume.

Also, injections aren't the most difficult part of living with diabetes, he tells WebMD. "It's taking blood sugar readings and making adjustments based on what you are eating and doing that makes taking insulin difficult whether as a pill, inhaled, or a skin cream."

In addition, Jackson says needles today are so small, fine, and short that we can guarantee that less than one in 200 people will feel pain.