Dodging The Needle?

Those who dread hypodermic needles may someday be able to apply their medicine on their skin instead, a couple of researchers believe.

Two University of Toronto chemists, Dr. Geoffrey Ozin and postdoctoral fellow Dr. Kai Landskron, announced recently they had created an unusual material using man-made molecules called dendrimers. They believe it can store drugs, and, when spread on the skin as a film, allow them to dissipate into a patient's bloodstream like a new type of patch.

However, the material is far from being on the market and must still undergo a lot more testing before researchers know whether it's safe or effective for humans.

What makes the material unique is that scientists think that it can deliver drugs to a person over a long period of time in amounts much smaller than from patches currently sold in drug stores.

This may solve a long standing dilemma for medical professionals and offer relief for millions of diabetes patients.

"The problem with current drug delivery systems like simple syringes is that when you inject the drug, you often inject initially too high a concentration to ensure it stays in the system, which can be toxic," said Landskron. "And if you inject too little into a person it's not effective."

The new material, called periodic mesophorous dendrisillicus, or PMD, would let drugs seep through a person's skin in just the right amount and stay at that level. The team also found they could change the patch's design to suit a specific drug or possibly even a person.

For people who suffer from conditions which require frequent injections, such as some diabetics who require daily doses of insulin, the discovery brings hope for an alternative to daily shots.

"It can be very stressful every day," said Angela Smith, a spokeswoman for the Canadian Diabetes Association. "They live with it the majority of their lives and a patch could make day to day living easier," she said.

The researchers declined to say when such a patch might hit the market, noting it first must overcome two challenges to reach the testing phase which itself could take a few years. The first task is to produce enough of it for experimenting. The second is cost. The team is looking for pharmaceutical companies to finance further tests.

Landskron and Ozin aren't alone in their type of research, but they're ahead of the pack.

"Right now the only place this (PMD) is in is Toronto," said Dr. James Baker, head of the Center for Biologic Nanotechnology at the University of Michigan, who is not involved in the Toronto researchers' project. "A lot of us would like to work with it."

However, dendrimers are expensive. "They're difficult to obtain and last time we (purchased them) they cost us US$128,000 per kilogram," Baker said.

The University of Toronto team believes these obstacles can be overcome. Landskron said slightly altering the type of dendrimers and their application should simplify PMD production and reduce costs.

"Cost is always an issue," but in terms of production he said, "I believe we can upscale it rather easily."