Non-Reactive Solvent Assisted Fractional Crystallisation for the Separation of Cannabinoids from Wax

A method has been developed by which cannabinoids are extracted from a waste wax that is formed during conventional extraction of cannabinoids from Cannabis plants. During medicinal cannabinoid extraction process, cannabinoids are extracted from the plant material into an alcohol phase, which can be regarded as a cold extraction process (i.e., no application of heat). However, cannabinoids are not extracted in pure form since several flavour compounds and waxes are co-extracted. To remove the waxes, the extraction solution is frozen at -40 °C to precipitate the wax in a step called winterisation. This step allows solidification of the waxes, which are then simply filtered out of the solution and removed from the processing stream. Currently, the cannabinoid industry is seeking alternative applications for these wax waste streams. However, because the waxes still entrap significant amounts of cannabinoids, most extraction companies stockpile the waxes with a view of adding value once an effective extraction has been developed to extract the residual cannabinoids. Stellenbosch’s solution manages to achieve this extraction and the method can unlock significant value within the cannabinoid industry for commercial extraction/purification facilities.

The extraction is obtained from a non‑reactive solvent assisted fractional crystallisation separating the cannabinoids from wax. The selection of the unique solvent along with optimised processing steps and conditions obtain a greater yield of high quality, medical‑grade cannabinoids.