Researchers investigate needle-free way to administer dental anesthesia
SÃO PAULO, Brazil: New findings from the University of São Paulo could bring relief to millions of people who are scared of needles. Using a tiny electric current, researchers were able to administer anesthetic in the mouth without a needle. Furthermore, this method delivered the drug faster and more effectively compared with an injection.
“Over the last few years, our research group has been working on the development of novel drug delivery systems for the treatment of several skin and eye diseases,” explained Dr. Renata Fonseca Vianna Lopez, one of the study authors and Associate Professor of Pharmaceutical Sciences at the University of São Paulo. “The skin and eyes pose challenges for drug delivery, so we have focused on improving drug delivery in these organs using nanotechnology, iontophoresis and sonophoresis, which is permeation using sound waves.”
In the study, the researchers added two anesthetic drugs, prilocaine hydrochloride and lidocaine hydrochloride, to common anesthetic hydrogels altered with a polymer to help the gels stick to the mouth lining. They then applied a tiny electric current to determine whether it made the anesthetic more effective—a process called iontophoresis.
In testing the method on the mouth lining of a pig, they found that the anesthetic was fast acting and long lasting. According to the researchers, the electric current made the prilocaine hydrochloride enter the body more effectively, increasing the permeation of the anesthetic through the mouth lining 12-fold.
Based on the results, the researchers now plan to develop an iontophoretic device to use specifically in the mouth. Although preclinical trials with the system need to be carried out in the future, the technology has the potential for application not only in dentistry but also in other medical areas, the researchers said.
“Needle-free administration could save costs, improve patient compliance, facilitate application and decrease the risks of intoxication and contamination,” said Lopez. “This may facilitate access to more effective and safe dental treatments for thousands of people around the world.”
Apart from hindering dental treatment, the fear of needles is a documented barrier to immunization in children and adults. A Canadian study conducted in 2012 among 1907 parents and children found that 24 percent of parents and 63 percent of children reported a fear of needles. Generally, it is estimated that about 10 percent of people suffer from the condition to a greater or lesser extent.
The study, titled “Needle-free buccal anesthesia using iontophoresis and amino amide salts combined in a mucoadhesive formulation,” was published in the December issue of the Colloids and Surfaces B: Biointerfaces journal.