March 27, 2000 (San Francisco) -- Imagine getting a vaccination without feeling any pain. Or using a super-effective inhaler that lets you take your medication by breathing rather than swallowing. Or, even better, having a dime-sized device implanted under your skin that dispenses drugs when your body calls for them.
These seemingly space-age devices aren't pipe dreams, but are drug delivery systems that are already in development -- and some of them could be available in a couple of years, say researchers at the annual meeting of the American Chemical Society, the world's largest scientific society.
"All these devices are very interesting work," says Prudence Bailey, PhD, a research and development scientist at Schering Plough Research Institute in Kenilworth, N.J. "They show how far we have progressed in drug delivery in just a few years."
Researchers at PowderJect Pharmaceuticals, led by Terry L. Burkoth, PhD, have successfully tested a device that blasts medications into the skin with a needleless jet-propulsion system. The device fires microscopic dry powder particles at supersonic speed through the top layer of the skin. From there, the drug finds its way into the blood system, where it can perform its function.
The only way a patient can tell that something has happened is that they hear a soft clap when the device is fired, and a red mark is left temporarily on their skin.
Burkoth and colleagues found the device to be effective when tested on eight healthy female volunteers, ages 18-40, using a drug called calcitonin, which is used to lower calcium levels. The device, Burkoth says, could potentially be used to administer vaccines with minimal discomfort.
"The work is interesting, but I think it still has to prove benefits before it is ready for widespread use," W. Mark Saltzman, PhD, tells WebMD. Saltzman is a professor of chemical engineering at Cornell University in Ithaca, N.Y.
But another device, the electronic inhaler, may be ready for prime time, Saltzman says. "Inhalers have been around for a long time," he says, "but these people do it better than anyone else."
Conventional inhalers deliver varied amounts of medication to the large airways of the lungs. The new device, though, can deliver precise doses of tiny liquid particles into the small airways -- a much more efficient method.
According to Igor Gonda, PhD, a researcher at Aradigm Corp. in Hayward, Calif., the device monitors how a patient is inhaling, and when the breaths are slow and controlled, it emits a green light to signal that the drug is about to be administered. A piston pushes the drug from its blister pack into the airstream, where it is inhaled. The patient holds his breath for a few seconds to allow the drug to concentrate in the lungs.
Gorda says that the device could be used in treating diabetes, cystic fibrosis, or chronic pain, and may even play a role in delivering gene therapy. He adds that use in asthma and other lung disorders is also possible.
Another researcher here suggests that implantation of a dime-sized microchip may make needles a thing of the past. The chip, when placed under the skin, would contain hundreds of mini-reservoirs capable of dispensing medications on demand, says John Santini Jr., PhD, president of MicroCHIPS Inc. of Waltham, Mass.
Santini and colleagues from the Massachusetts Institute of Technology have tested the chips in the laboratory and are planning to test them in animals soon. He said the devices could deliver drugs used to control chronic pain, in cancer therapy, in hormone therapy, and for other conditions.
"This is very intriguing work," says Saltzman, "but it is very preliminary."