Because essential oils are lipids, they do not readily mix with water. The ability of hydrophobic essential oil constituents to travel through the water-based bloodstream and access cellular targets is weak in comparison to water-soluble compounds. Some researchers have recently begun to hypothesize that the activity of essential oils might be greatly enhanced if there were a way to help them mix with water.
Nanoemulsion technology does exactly that. Normally oil-water mixtures naturally form an emulsion, which consists of droplets of oil suspended in water. Nanoemulsions, on the other hand, are created using a surfactant and a powerful preparation technique involving ultrasonic vibration or intense heating and cooling procedures. This creates infinitesimal droplets between 20 and 200 nm in size, aptly called “nanodroplets.”
A new study published in the journal Inflammopharmacology showed how nanoemulsions greatly amplified the effects of an essential oil. The authors compared Rosemary essential oil to a rosemary oil nanoemulsion in a series of experiments. In an experimental model of edema, Rosemary essential oil was effective at a dose of 300 mg/kg. The nanoemulsion had the same effects at a dose 600 times lower! Only 0.5 mg/kg body weight was required to exert the same effect.
In another experiment, the researchers tested Rosemary’s soothing effects. The effective dose of the rosemary nanoemulsion was more than 100 times lower than the effective dose of raw Rosemary oil. In yet another experiment, the researchers measured the ability of the raw oil and the nanoemulsion to protect the gastrointestinal tract. One hundred mg/kg of the Rosemary successfully provided protection, while the nanoemulsion was effective at all measurement stages of the experiment at just 0.5 mg/kg. That’s 200 times lower than the concentration of the raw essential oil.
Essential oils are already known for their powerful biological activity. By increasing their miscibility in water, essential oil constituent molecules can become more bioavailable, thereby increasing their potency as biological effectors. Using nanoemulsions, the effect of Rosemary oil was amplified more than 100 fold in this study.
While the amplification of essential oil activity is an exciting concept, it comes with safety concerns as well. Raw oils are known to be quite safe; however, the powerful nanoemulsions may or may not require special procedures to be used safely. Little is understood about the clinical application of nanoemulsions at this time. This much is certain: further research on this new technology will lead to exciting new applications of essential oils in healthcare.