In response to the growing demand for concentrates, cannabis product manufacturers are exploring new technological advances in cannabinoid extraction methods. Recent developments in extraction techniques support the customization of terpene profiles and development of concentrates that offer patients routes of drug delivery beyond smoking medical cannabis flower. This form of “agro-chemical” engineering will play an increasingly important role in future research and therapeutic application of over 500 cannabis compounds.
To understand the evolution of ethanol extraction, it is important to review two main forms of commonly used extraction methods: solventless and solvent-based. Solventless is a simple but time-consuming process, and it is not easily scalable in terms of business operations. Larger companies can easily produce these specialized solventless concentrates on an industrial scale, but smaller cannabis manufacturers may not find this process cost-effective or manageable with a smaller workforce.
Solvent-based extraction uses solvents such as ethanol, butane, CO2 and other liquid gases to extract cannabinoids from plant material. CO2 extraction has been used effectively with extracting caffeine from coffee beans, and ethanol is used to extract compounds from many plants. The process of extraction involves passing a liquid solvent through raw vegetation, and either cold or warm temperatures can be used to facilitate the process. The solvent isolates desired components and filters out unwanted components. After the solvent evaporates, the extracted compounds are ready for final product formulation in concentrates, topical solutions, and vaping oils.
Alternative methods of extraction include ultrasonic assisted, microwave assisted, and pressurized liquid extraction processes. Supercritical CO2 extraction is more environmentally friendly than most extraction processes. However, more research needs to be conducted to determine the efficacy and environmental footprint of each technique.
University of North Carolina Charlotte researchers conducted a study of extraction that examined differences in commercial and amateur solvent extraction methods. Their research also revealed the participants preferred the distinct psychoactive effects of concentrates over those of flower and other cannabis products, which may offer insight into future consumer demands for a broader range of concentrates including rosin, shatter, hash, wax, and oil that possess specialized cannabinoid formulations.
Some researchers believe that extraction technologies will have to keep pace with market demands by identifying the right chemical, timing, and temperature for extracting compounds from different strains. A recent article in The Scientist highlights how one researcher described this work as, “...almost trial and error, where we're researching with a variety of acids and oxidizers for isomerizations and dehydrogenations for making novel compounds.” Extracting for specific terpene profiles and creating new compounds will have implications for managing different disorders and symptoms.