NEW research could lead to insulin pills instead of shots

Sunday, August 26th 2001, 12:00 am
By: News On 6

CHICAGO (AP) _ Purdue University scientists believe they've found a way to make insulin for diabetics available in pills instead of daily shots.

The breakthrough is a new acrylic-based, gel-like coating on the pills to improve the body's absorption of insulin.

Injections under the skin allow insulin to be absorbed slowly enough to control blood sugar levels. But efforts to control diabetes with insulin pills have failed because the body digests them much too quickly.

The new product, so far tested only in diabetic rats and dogs, ``can potentially overcome these barriers,'' said researcher Nicholas Peppas, a professor of chemical and biomedical engineering at Purdue.

The material he developed with graduate student Aaron Foss would allow pills to survive the harsh digestive acids in the stomach, and let insulin seep into the bloodstream through the small intestine, the researchers said.

Their research was among reports on Sunday's agenda at the start of the American Chemical Society's five-day national meeting in Chicago.

Insulin is a hormone produced by the pancreas that helps convert foods including sugar into energy. In diabetes, affecting about 16 million Americans, the body is unable to produce or properly use insulin, resulting in too much sugar in the blood. Some diabetics must inject themselves daily with insulin to help regulate blood sugar levels, but the shots can be painful, inconvenient and costly.

In tests on about 150 rats and dogs that were given pills coated with the new material, up to 16 percent of the insulin made it to the bloodstream, Peppas said. That compares with 50 percent to 80 percent with insulin injections, but it's still enough to control blood sugar, Peppas said.

Previous experimental insulin pills only allowed about 1 percent of the hormone to reach the bloodstream, he said.

The coating also could potentially be used with some injectable drugs used to treat cancer and osteoporosis, Peppas said.

Purdue has patented the product and is in discussions with interested pharmaceutical companies, which would do further tests in animals and humans, Peppas said. He said an oral product could make it to the market within the decade.

``It will be a very important quality of life improvement for patients to have an oral insulin available instead of having to rely on injectable forms,'' said Dr. Camillo Ricordi, scientific director of the Diabetes Research Institute at the University of Miami.

While most diabetics who require insulin use injections, alternatives include small insulin pumps, and research into inhaled insulin has shown promise. But some scientists say the most important research involves finding ways to avoid having to administer insulin.

Externally administered insulin can't completely keep fluctuating blood sugar levels under control, and diabetics are prone to a host of serious complications including eye, kidney and nerve damage.

``What we're doing now is imperfect because you can't match insulin to glucose levels,'' said Dr. Francine Kaufman, president-elect of the American Diabetes Association and a pediatric endocrinologist at Children's Hospital of Los Angeles.

She said a pill would be ``an answer but it's not THE answer.''

Ricordi said transplants of pancreatic insulin-producing islet cells at the University of Miami and elsewhere have shown promise in keeping humans off insulin, but they're still experimental.