‘Fantastic Voyage,’ Revisited: The Pill That Navigates

By ANNE EISENBERG

01 feb 2009--THE doctor’s advice to “take two aspirin and call me in the morning” may one day be updated to “take this pill, and it will call me in the morning.”

Philips Research in Eindhoven, the Netherlands, has developed a prototype for a pill that can be programmed to navigate toward a specific trouble spot in the body and deposit its medicine there, radioing dispatches to the doctor as it travels.

The technology, now being tested in animals but not yet in humans, may one day be used to treat digestive tract disorders like colitis and Crohn’s disease, said Dr. Peter van der Schaar, a gastroenterologist in Heerlen, also in the Netherlands. He worked with Philips in developing the device, which is officially named the Intelligent Pill and which Philips calls the iPill for short.

The iPill, a plastic capsule that is to be taken with food or water, is intended to travel through the digestive system naturally, typically within about 24 hours, dispensing its medicine at specific locations along the way, Dr. van der Schaar said.

Localized drug delivery has advantages: it can mean smaller doses of a drug, as well as fewer problems than when the drug travels through the body in the bloodstream. “The drugs might have fewer side effects while having a higher therapeutic value,” he said.

About the size of a plump multivitamin, the iPill is one-third medicine and two-thirds microprocessor, battery, antenna and other miniaturized equipment. The pill can send data to a control station about temperature, for example, and the time that has elapsed since it was swallowed. And the medical staff can then respond.

“If a doctor sees an adverse reaction,” said Steve Klink, a senior communications manager at Philips Research, a signal could be sent “to override the iPill and not distribute any more of the drug.”

Michael J. Cima , a professor of materials science and engineering at the Massachusetts Institute of Technology and an investigator at the Koch Institute for Integrative Cancer Research there, said that electronic systems for localized drug delivery were already being used in clinical testing of pharmaceutical products. For example, a volunteer swallows a pill that is tracked with X-rays and programmed to release its medicine at a specific spot in the gastrointestinal tract — for instance, in the colon.

The pills aren’t yet in use in the general population. But Philips Research, an arm of Philips Electronics, may be well placed to bridge that gap, Mr. Cima said. “Those folks are in consumer electronics,” he noted.

Basic to the iPill’s successful journey is a sensor within it that detects the acidity, as measured by the pH value, in the gastrointestinal tract. This varies from the high acidity of the stomach to the less acidic intestines to the more acidic colon. “We can program the pill to do a certain mode of action based on this change of pH,” Dr. van der Schaar said.

The medication is packed into a reservoir within the pill and can be released all at once or in bursts as it travels along, Mr. Klink of Philips said. A tiny pump inside the pill releases the drugs. The pump, made up of a motor and piston driven by a screw rod, is commanded by the microprocessor. A silver oxide battery in the pill lasts about two days, twice the time it usually takes for the pill to travel naturally through the body.

The device is being tested at the Philips Research laboratories in Briarcliff Manor, N.Y., said Jeff Shimizu, a senior scientist. Researchers are using an aquarium as a stand-in for the watery medium of the human body, testing the propagation of the iPill’s radio waves as they make their way from the tank to the receiving station.

“It’s working out pretty well,” Mr. Shimizu said.

Another company that has developed technology to deliver drugs to specific regions of the gastrointestinal tract is Pharmaceutical Profiles Ltd. of Ruddington, England. It specializes in clinical trials for pharmaceutical and biotechnology customers. More than 3,500 capsules packed with drugs, an antenna, electronics, and other materials have been ingested by volunteers using the Pharmaceutical Profiles technology, called Enterion, since 2002, said Dr. Mark Egerton, managing director. Dr. Cima of M.I.T. said that one day, localized electronic drug delivery might play an important role in patient care.

“You could put a drug to treat colon cancer or irritable bowel syndrome at a select location in the G.I. tract with great fidelity,” he said. “It could be the next step in therapy.”