Sonication, or ultrasonication, is a soundwave technology widely used in biofuels, pharmaceuticals, wastewater processing, and other major industries. It's also necessary for nanoemulsions and other nanoparticle production — which might sound familiar as it's now widely used within the cannabidiol (CBD) sector too.
But, ultrasonic technology may be helpful for more than just nanoemulsion. This high-frequency technology is getting applied to the extraction side of the industry as well.
By and large, the cannabis extraction world today relies almost exclusively on traditional extraction technologies that use solvents, heat, and pressure. But what if there was a way to improve upon the current solvent standards?
Ultrasonic extraction, or sonication, improves solvent-based extractions by:
- Shortening processing time
- Increasing extraction rate
- Lowering temperatures to preserve volatile cannabinoids
- Improving safety
- Simplifying operation
- Reducing environmental impact
An Ultrasonic Explainer
Sonication works by creating microscopic bubbles. Using ultrasonic waves — or sound waves that are well beyond the frequency perceptible by the human ear — this technology compresses and expands whatever solution it's immersed within.
The high-pitched and inaudible frequency naturally produces bubbles in the solution, which inflate and then collapse. One source references this as a “violent collapse,” known scientifically as cavitation. Eventually, this aggressive microscopic activity breaks down the cellular walls. As a result, the cell contents — cannabinoids, terpenes, and more — wash out into the solution.
Several factors influence the efficiency of ultrasonic technology in cannabinoid extraction: temperature, time, solvent, and frequency. Playing around with these variables impacts the nanoparticle size and extraction time.
Ultrasonic Emulsification, aka Nanoemulsion Technology
Naturally, cannabinoids like CBD and THC have low bioavailability. When consumed orally (through the digestive tract), the human body absorbs relatively low levels of cannabinoids. The molecules are also hydrophobic, meaning they don't mix well with water — part of the reason why it took so long for cannabis-infused drinks to take off.
Ultrasonic emulsification makes cannabinoids more bioavailable but also improves cannabinoid dispersion in water. When exposed to ultrasonic wavelengths, cannabinoids break down into tiny particles between one to 100 nanometers in size. These new nanoparticles seamlessly move between the water molecules for clear and stable emulsification.
Cannabis drink producers are adopting this technology to make clear, properly emulsified, and appealing cannabis drinks. Chances are, one of your favorite THC-infused beverages uses ultrasonic technology to incorporate the cannabinoids into the formula thoroughly. Nano CBD is also one of the latest trends in the booming CBD industry, with just about every major producer now offering at least one nanoemulsion formulation.
Sonication as a Faster and More Efficient Extraction Technology
But ultrasonic technology could offer much more to producers than just advanced emulsification. It starts with the standard solvent-based methods, then improves upon them.
To start, sonic extraction protects many of the more volatile compounds found in cannabis because it uses much lower temperatures than other, more traditional means of extraction. If the parameters are correct, it also takes significantly much less time and produces a far greater yield than traditional technologies.
Several recent publications have explored the efficiency, speed, and yields of ultrasonic technology for cannabinoid extraction. In just about every study, authors find substantial benefits to ultrasonic extraction.
In one of the most interesting examples from 2018, Charu Agarwal, Katalin Math et al. compared an ultrasonic extraction to a more traditional extraction.
The experiment placed 2.5 mg of plant material into various methanol solutions. The researchers stirred the control preparation continuously. The other solution was treated with a probe sonicator set to 20 kHz. After stirring and sonication, each preparation was placed in an oven to evaporate the solvent. The researchers then analyzed the remaining extraction.
The researchers discovered that in each area (phenols, flavonoids, the ferric reducing ability of plasma, and cannabinoid yield), the sonication sample delivered “noticeably higher values.” Most importantly, “ultrasound considerably improved the extraction of cannabinoids present in Cannabis.”
According to Sound Extractions, “Sonic extraction fully infuses all cannabinoids, terpenes, and flavonoids into any carrier oil in minutes with efficiencies above 95%.” Sound claims this technology produces concentrations of up to 10 percent of total cannabinoids by weight. The substantial improvements to yield and efficiency are some of the many reasons why producers are adopting this technology across the extraction sector.
Sonication: The Next Wave of Cannabis Extraction
Technologies like ultrasonic extraction are giving processors an edge in a highly competitive space. In some of America's most established markets, extraction sales grew by 40 percent in 2020.
Extractors and processors seek new ways to cut costs, improve yields, and deliver the full-spectrum product that consumers demand. In short order, sonication may become the new industry standard.