HP researchers have developed a medical patch, based on the thermal inkjet technology found in printers, to painlessly administer drugs to patients.
The patch uses microneedles to inject drugs just below a patient’s skin and can be programmed to precisely control the amount and timing of each dose that is delivered, says John O’Dea, CEO of medical device manufacturer Crospon, which has licensed the patch and plans to develop it into a commercial product.
“Microneedles are a new and upcoming transdermal drug delivery technology,” O’Dea says.
But the inkjet technology used in the patch isn’t exactly the same as that used in HP printers.
HP’s inkjet printer technology uses a “superheated vapour explosion lasting just two-millionths of a second” to deliver a drop of ink to a piece of paper, according to the company’s website.
The patch employs a modified version of this technology, using a different material that expands when heated to deliver the drug, says Lim Eng Hann, associate director of intellectual property licensing at HP.
While the microneedles penetrate the skin, the patch is painless to use. “The microneedles are designed in such a way that they don’t penetrate the skin deep enough to impact the nerves,” Lim says.
Nerves are located approximately 700 microns, or millionths of a metre, below the top layer of skin. But the microneedles will only penetrate 75-100 microns, O’Dea says.
Equipped with basic electronics and a power source, the microneedle patch measures roughly 2.5 centimetres square, and is 3 millimetres thick. The patch will pack between 400 to 1,000 microneedles and include a power source, such as a battery, as well as electronics to control when drugs are administered and in what quantity.
Despite the electronics, HP’s patch is broadly similar to the transdermal nicotine patches used to help people stop smoking. But where nicotine can be absorbed through the skin, HP’s microneedles penetrate the skin and can deliver drugs, such as biopharmaceuticals, that have molecules too large to be absorbed through the skin.
HP’s microneedle patch can also be used to deliver several different drugs, and is well suited to situations where a patient requires timely delivery of these drugs, O’Dea says.
Crospon plans to develop the patch further and will work with pharmaceutical companies to bring the product to market, O’Dea says. That process will take six to nine months, and a commercial product could be available in about three years’ time, pending regulatory approval, he says.