NEW YORK – An innovative drug delivery system comprising nanoparticles quickens response in erectile dysfunction (ED), says a new study.

“The response time…was… just a few minutes, which is basically what people want in an ED medication,” said study co-author Kelvin P. Davies.

“In both rats and humans, it can take 30 minutes to one hour for oral ED medications to take effect,” said Davies, associate professor of urology at Albert Einstein College of Medicine.

Besides, “an estimated 30 to 50 percent of men with ED do not respond to oral use of (such) PDE5 inhibitors (class of drugs called phosphodiesterase type 5),” adds Davies.

The new system, after successful testing in rats, could potentially prevent side-effects associated with oral ED medications in humans.

The drug-delivery system, developed by Einstein College scientists, can carry tiny payloads of various drugs or other medically useful substances and release them in a controlled and sustained manner.

That could spell safer and more effective ED therapy for millions of men with heart disease and other health problems affecting erectile function.

Tens of millions of men worldwide have benefited from oral ED medications such as sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis).

However, these medications – which belong to PDE5 inhibitors – have limitations. They can cause systemic and serious side-effects.

They include headache, facial flushing, nasal congestion, upset stomach, abnormal vision as well as isolated reports of hearing and vision loss.

Men who have recently suffered a heart attack or stroke or have severe heart disease should use these drugs with caution or not at all.

This study was done to evaluate whether the nanoparticles, which have been shown to penetrate the skin, might allow the targeted delivery of compounds that treat ED and thereby avoid the drugs’ systemic effects.

“Most of the animals, nearly 90 percent, showed a response to treatment with the nanoparticles,” says co-author Joel M. Friedman, Einstein College professor of physiology, biophysics, medicine.

Friedman developed the nanoparticles with his son Adam Friedman, chief resident in the division of dermatology at the college.

Clinical studies on humans could begin in a few years if animal studies continue to show that the nanoparticle delivery system is safe and effective, says a college release.

The study was published in the online edition of the Journal of Sexual Medicine.