Antibiotic gel offers easier way to treat ear infections

Scientists said Wednesday they have developed a gel-based ear drop that may one day make taking antibiotics much easier and potentially safer for toddlers with ear infections.

When applied, the gel can deliver an entire course of antibiotics directly into the ear, avoiding systemic side effects and drug resistance associated with oral antibiotics, they reported in the U.S. journal Science Translational Medicine.

Middle-ear infection, or otitis media, affects 95 percent of children, prompting 12 to 16 million clinical visits per year in the U.S. alone.

Patients are typically prescribed a 10-day course of oral antibiotics, which are often challenging for young children to take.

"Force-feeding antibiotics to a toddler by mouth is like a full-contact martial art," said Daniel Kohane, the study's senior investigator and director of the Laboratory for Biomaterials and Drug Delivery at Boston Children's Hospital.

Furthermore, parents often stop treatment too soon since children seem to get better within a few days, which can raise the risk of bacterial resistance.

And because high doses are needed to get enough antibiotic to the ear, side effects like diarrhea, rashes and oral thrush are common.

"With oral antibiotics, you have to treat the entire body repeatedly just to get to the middle ear," said Rong Yang, a chemical engineer in Kohane's lab and first author on the paper. "With the gel, a pediatrician could administer the entire antibiotic course all at once, and only where it's needed."

Antibiotics reformulated as ear drops are a long-sought alternative, but the eardrum poses an impenetrable barrier to many drugs.

The new gel contains lipids that can help the antibiotic, ciprofloxacin, cross the eardrum into the middle ear, where it is slowly released over a week.

"Our technology gets things across the eardrum that don't usually get across, in sufficient quantity to be therapeutic," said Kohane.

When tested in chinchillas, rodents with a hearing range and ear structure similar to those of humans, the gel completely cured ear infections due to Haemophilus influenzae bacteria, a common cause of otitis media, in 10 of 10 animals.

According to the researchers, the drug flowed directly into the middle ear and was undetectable in the bloodstream, suggesting the chinchillas were likely spared from systemic toxicity.

The gel melted away within three weeks and the rodents' eardrums appeared normal after treatment, they said.

In contrast, ordinary ciprofloxacin ear drops cleared the infection in only five of eight animals by day seven.

Though further studies are needed, Kohane hoped to form a company that would begin testing the gel in patients in the next few months. Enditem