Microneedle patch delivers painkiller to second layer of skin in 5 minutes

Microneedle patch--Courtesy of National University of Singapore

Researchers in Singapore have developed a microneedle patch capable of delivering the painkiller lidocaine with just 5 minutes of application, a far cry from the 45 minutes they say is required of those commercially available now.

For pain, speed of delivery is important but hindered by absorption factors in the skin--different patients require different kinds of patches due to skin variability. To get past that hurdle, the scientists from the National University of Singapore created their patch with polymeric needles just 600 micrometers in length that keep pores open in the skin for fast, continuous delivery.

Current transdermal patches administer lidocaine topically, according to the abstract published in the journal Molecular Pharmaceutics. But the new patch's needles extend into the dermis, or the second layer of skin. This speeds up the delivery significantly and produces a faster analgesic effect. The patch holds the drug in a reservoir and sends it through tiny channels created in the skin by the needles.

In an in vitro study on rat skin, the patch delivered 70 mg of lidocaine in as few as 5 minutes and at a higher volume. And the scientists tested the patch on themselves to demonstrate a pain-free incursion of the needles into the skin.

And what's more, painkillers aren't the only drug that could be delivered with the microneedle patch. Skincare products such as collagen, currently delivered to the outer layer of the skin, are more effective when delivered deeper. And in pediatric care, a small amount of lidocaine can be delivered with a microneedle "sticker" to reduce the pain of a vaccine jab.

- here's the NUS report
- and here's the abstract