A team of chemical engineers at MIT has devised a new method to form tiny droplets of one liquid suspended in another liquid, dubbed ‘nanoemulsion.’ These emulsions are extremely small in size, which allows them to retain their form for extended lengths of time. The researchers have also found an easy way to convert the liquid nanoemulsions to a gel when at body temperature i.e., 37 degrees Celsius, which might help the development of new materials to deliver medications when it is exposed to the skin or injected in the body.
In the research, the team was successful in creating nanoemulsions that lasted for over a year. The researchers inserted ibuprofen inside the droplets to exhibit the emulsions’ potential applications for delivering drugs. Patrick Doyle, the Robert T. Haslam Professor of Chemical Engineering and senior author of the research, stated that the pharmaceutical industry is fascinated by nanoemulsions as a way to deliver small molecule therapeutics. This could be achieved topically, through injestion, or by spraying into the nose, because if one starts getting into the size range of hundreds of nanometers, one can penetrate much more efficiently into the skin. The lead author of the study is Seyed Meysam Hashemnejad, a former MIT postdoc along with Abu Zayed Badruddoza, former postdoc; L’Oréal senior scientist Brady Zarket; and Carlos Ricardo Castaneda, former MIT summer research intern. One of the easiest ways to formulate an emulsion is to add energy, by adding a homogenizer to break down fat globules present in milk. The energy input and the size of the droplets are inversely related, and higher energy also results in more stable water droplets.
Nanoemulsions that consist of droplets with a diameter 200 nanometers or smaller are preferred not only because they are more stable, but they also have a higher ratio of surface area to the volume that lets them carry larger payloads of active components like drugs or sunscreens. The findings of the team have been published in Nature Communications.