New pump created for microneedle drug-delivery patch

September 1, 2010 by Emil Venere
Purdue doctoral student Charilaos Mousoulis demonstrates a prototype pump for drug-delivery patches that might use arrays of microneedles to deliver a wider range of medications than now possible with conventional patches. (Purdue University photo/Birck Nanotechnology Center)

( -- 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 , 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 , 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.

"It's like a bandage - you would use it and discard," Ziaie said.

The patches require a pump to push the drugs through the narrow needles, which have a diameter of about 20 microns, or roughly one-fourth as wide as a human hair. However, pumps on the market are too complex for patches, he said.

"We have developed a simple pump that's activated by touch from the heat of your finger and requires no battery," Ziaie said.

The pump contains a liquid that boils at body temperature so that the heat from a finger's touch causes it to rapidly turn to a vapor, exerting enough pressure to force drugs through the microneedles.

"It takes 20 to 30 seconds," Ziaie said.

The liquid is contained in a pouch separated from the drug by a thin membrane made of a rubberlike polymer, called polydimethylsiloxane, which is used as diaphragms in pumps.

Research findings are detailed in a paper being presented during the 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences on Oct. 3-7 at University of Groningen in The Netherlands. The paper was written by electrical and computer engineering doctoral students Charilaos Mousoulis and Manuel Ochoa and Ziaie.

Researchers have filed an application for a provisional patent on the device.

Ziaie has tested prototypes with liquids called fluorocarbons, which are used as refrigerants and also in semiconductor manufacturing.

"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."

Findings indicate prototypes using the fluorocarbon HFE-7000 exerted 4.87 psi and another fluorocarbon, FC-3284, exerted 2.24 psi.

Explore further: Wireless cancer treatment device developed

More information:

Related Stories

Wireless cancer treatment device developed

April 18, 2006

Purdue University scientists are building a tiny wireless device that could be implanted in tumors to register the precise dose of radiation received.

Ceramic hybrid needles take the sting out of shots

January 7, 2008

New polymerization technology may one day take the pain out of injections and blood draws. A team of researchers at the University of North Carolina and Laser Zentrum Hannover have recently used two-photon polymerization ...

Microneedles enhance drug administration through skin

February 4, 2008

In what is believed to be the first peer-reviewed study of its kind involving human subjects, researchers at the University of Kentucky College of Pharmacy and the Georgia Institute of Technology have demonstrated that patches ...

Microneedles Could Replace Syringe

March 10, 2008

The common needle phobia and painful injections could soon be a thing of the past, thanks to a revolutionary new drug-delivery technique developed by a team at the Georgia Institute of Technology, US. The long-practiced method ...

'Ferropaper' is new technology for small motors, robots

January 5, 2010

( -- Researchers at Purdue University have created a magnetic "ferropaper" that might be used to make low-cost "micromotors" for surgical instruments, tiny tweezers to study cells and miniature speakers.

Recommended for you

Moonlighting molecules: Finding new uses for old enzymes

November 27, 2015

A collaboration between the University of Cambridge and MedImmune, the global biologics research and development arm of AstraZeneca, has led researchers to identify a potentially significant new application for a well-known ...

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Sep 01, 2010
Why the people like to take drug, this is not good for our health.
not rated yet Sep 01, 2010
I would hope this is a very cheap device when made in quantity because diabetics might be able to use it.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.