Physics News

Purdue University researchers have developed a new type of pump for drug-delivery patches that might use arrays of "microneedles" to deliver a wider range of medications than now possible with conventional patches.The current "transdermal" patches are limited to delivering drugs that, like nicotine, are made of small hydrophobic molecules that can be absorbed through the skin, said Babak Ziaie, a professor of electrical and computer engineering and biomedical engineering."There are only a handful of drugs that currently can be administered with patches," he said. "Most new drugs are large molecules that won't go through the skin. And a lot of drugs, such as those for treating cancer and autoimmune disorders, you can't take orally because they aren't absorbed into the blood system through the digestive tract."Patches that used arrays of tiny microneedles could deliver a multitude of drugs, and the needles do not cause pain because they barely penetrate the skin, he said.

"There are only a handful of drugs that currently can be administered with patches," he said.
"It's like a bandage - you would use it and discard," Ziaie said.
"We have developed a simple pump that's activated by touch from the heat of your finger and requires no battery," Ziaie said.
"You need a relatively large force, a few pounds per square inch, to push medications through the microneedles and into the skin," Ziaie said. "It's very difficult to find a miniature pump that can provide that much force."