Pure Green Pharmaceuticals was recently issued a patent (US Pat. 10,729,734) for a cool new way of extracting cannabinoids - that is using freeze-drying. Freeze-drying cools and freezes a cannabis plant so that it may be ruptured then extracted with a solvent. The patent mentions using carbon dioxide as the solvent for extraction. 

Pure Green pushes for a cannabis-derived CBD with micro-doses of THC rather than hemp-derived “to yield real, symptom-specific medicine that is safe for both acute and chronic problems.” Founded by Stephen Goldner, the man who invented liquid methadone for addicts, Pure Green is focused on researching and developing science-backed cannabinoid medicines to help treat a multitude of issues. 

Cannabis extraction processes continue to be developed and will be for a while until cannabinoid biosynthesis mass-scaling is perfected through R&D. For more information on cannabinoid biosynthesis, see this article published on Magic Number.  

Cannabis processing is the third most active area of patent filings. Take a look using the interactive visual Cannabis Patent Forecast® by Magic Number.