Skin is often considered a viable mode of drug delivery because of its higher absorption rate and targeted delivery option. However, penetrating drugs through the skin isn't always easy as it requires bulky devices. A group of scientists has now come up with a light and wearable skin patch that will make the approach a whole lot easier for both the medics and the patient.

The groundbreaking innovation delivers painless ultrasonic waves to the skin, creating tiny channels for the drug to pass through, the Massachusetts Institute of Technology (MIT) said in a news release.

Researchers were exploring some alternatives to the existing methods of delivering drugs.

"The main benefit with skin is that you bypass the whole gastrointestinal tract. With oral delivery, you have to deliver a much larger dose in order to account for the loss that you would have in the gastric system," said Aastha Shah, one of the lead authors of the paper. "This is a much more targeted, focused modality of drug delivery."

How does it work?

Ultrasound exposure is key to enhancing the skin's permeability to drugs. The device has been equipped with several disc-shaped piezoelectric transducers that convert electric current into mechanical energy.

For their study, which was published in Advanced Materials, the research team diluted the drugs in a liquid solution and filled them into the polymeric cavities of the device. When the piezoelectric elements come in contact with electric current, they generate pressure waves in the fluid, generating bubbles that burst against the skin. This creates microjets that seep down through the epidermis by effortlessly crossing the skin's tough outer barrier, the stratum corneum.

What is it made of?

The patch is made up of PDMS, a silicone-based polymer that can adhere to the skin without tape. Researchers tested the device by delivering a B vitamin called niacinamide through the skin. Niacinamide is a component that is used in skincare products.

In the tests using pig skin, researchers found the absorption of the drug was 26 times higher than the amount that could pass through the skin without ultrasonic assistance.

Researchers hope the new device could be used to deliver hormones, muscle relaxants and other drugs through the skin.

"After we characterize the drug penetration profiles for much larger drugs, we would then see which candidates, like hormones or insulin, can be delivered using this technology, to provide a painless alternative for those who are currently bound to self-administer injections on a daily basis," Shah said.

Microneedle Vaccine Patch
The vaccine patch contains microneedles that dissolve into the skin. Photo courtesy of Pixabay