'Contraceptives may soon be administered via pain-free patch'

Scientists have designed a novel long-acting contraceptive that can be self-administered by women using a painless microneedle skin patch.

The research, published in the journal Nature Biomedical Engineering, may pave the way for a new family planning option, particularly in developing nations where access to healthcare can be limited.

Long-acting contraceptives now available provide the highest level of effectiveness, but usually require a healthcare professional to inject a drug or implant a device.

Short-acting techniques, on the other hand, require frequent compliance by users and therefore are often not as effective.

In animal testing, an experimental microneedle contraceptive patch provided a therapeutic level of contraceptive hormone for more than a month with a single application to the skin.

When the patch is applied for several seconds, the microscopic needles break off and remain under the surface of the skin, where biodegradable polymers slowly release the contraceptive drug levonorgestrel over time.

Originally designed for use in areas of the world with limited access to health care, the microneedle contraceptive could potentially provide a new family planning alternative to a broader population.

"There is a lot of interest in providing more options for long-acting contraceptives," said Mark Prausnitz, a professor at the Georgia Institute of Technology in the US.

"Our goal is for women to be able to self-administer long-acting contraceptives with the microneedle patch that would be applied to the skin for five seconds just once a month," Prausnitz said.

Long-acting contraceptives are now available in formats such as patches that must be worn continuously, intrauterine devices (IUDs) that must be placed by trained healthcare professionals, and drugs injected with hypodermic needles.

If the microneedle contraceptive patch is ultimately approved for use, it could become the first self-administered, long-acting contraceptive that does not involve a conventional needle injection, researchers said.

Like other long-acting contraceptive techniques, the microneedle contraceptive patch would disrupt the menstrual cycles of women using it.

Testing with rats evaluated only the blood levels of the hormone and did not attempt to determine whether it could prevent pregnancy.

"The goal was to show that we could enable the concentration of the levonorgestrel to stay above levels that are known to cause contraception in humans," Prausnitz said.

"We do not yet know how the contraceptive microneedle patches would work in humans," Prausnitz said.

"Because we are using a well-established contraceptive hormone, we are optimistic that the patch will be an effective contraceptive," he said.

"We also expect that possible skin irritation at the site of patch application will be minimal, but these expectations need to be verified in clinical trials," he added.

The researchers aim to develop a patch that could be applied once every six months.