The market is swimming with ear infection drugs, but keeping up with frequent ear-drop doses can be a metaphorical headache—and a literal earache. But a group of scientists at the University of Montana have developed a temperature-stable, single-dose option, and they have new preclinical data to back it up.
Plenty of existing antibiotics can treat acute otitis externa—also known as swimmer’s ear—but patients typically have to take ear drops multiple times a day for several weeks. A single-application gel taken at home could improve adherence, potentially curb bacterial drug resistance and expand access to those living in remote areas, the researchers figure.
Led by Monica Serban, Ph.D., the team developed two separate hydrogel delivery systems and tested them in a cell and mouse study published in the journal ACS Biomaterials Science & Engineering.
Both systems combine activated tetraethyl orthosilicate with different large molecules to create a hydrogel, which remains in a liquid state inside a syringe, but quickly forms a gel upon entering the ear, allowing for sustained drug release.
The team paired those hydrogel systems, stable from about 39 degrees to 104 degrees Fahrenheit, with the antibiotic ciprofloxacin, which itself doesn’t require refrigeration.
In cell cultures, the drug-infused hydrogels managed to wipe out the bacteria Pseudomonas aeruginosa and Staphylococcus aureus—the two major culprits behind swimmer’s ear—at doses 100 times lower than those used in most ear drops, the team said.
The gels also proved safe when tested on models of human skin and dissipated within 10 days in mouse ears. They had no significant impact on the mice’s hearing compared to standard ear drops, the team added.
Serban’s lab recently snared a $1.45 million award from the National Institute of Health for its ear infection efforts, which will allow the team to run further tests on shelf life and stability, ABC Fox Montana reported. If all goes to plan, the product could hit shelves in about two years, the team figures.
Meanwhile, the FDA in 2018 greenlighted Otonomy’s ciprofloxacin otic suspension, sold as Otiprio, as the first single-dose antibacterial approved to treat swimmer’s ear.
The drug, first cleared in 2015 to treat young children undergoing tympanostomy tube placement surgery, eliminates outer ear infections after a single dose, but Otiprio must be refrigerated and prepared before use. A medical professional must also administer the drug in the clinic—factors Serban’s team hope to overcome with its room temperature-stable delivery platform.