Heat-activated pump could enhance drug-delivery patches

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 auto-immune disorders, you can’t take orally because they aren’t absorbed into the blood system through the digestive tract.’

Patches that use arrays of tiny microneedles could deliver a multitude of drugs, and the needles do not cause pain because they barely penetrate the skin, he added.

The patches require a pump to push the drugs through the needles, which have a diameter of about 20 microns. However, pumps on the market are too complex for patches, he said.