Chapter 2 - Medical cannabis and cannabinoids: How best to extract components from plant material

Abstract

There are diverse methods to extract cannabinoids from Cannabis, including conventional and advanced techniques. In selecting the proper method, several parameters have to be considered, mainly solvents, time of extraction, temperature, pressure, size of the plant material, and matrix/solvents ratio. Basing on the current literature, the use of organic solvents is the most convenient method for cannabis extraction. Among the conventional methods, Soxhlet extraction and dynamic maceration gave the best results, even though these techniques are time-consuming and with harmful environmental impact, furnishing also low yields and low quality of extracts. For this reason, several advanced techniques have been developed, including pressurized liquid extraction, ultrasound-assisted extraction, supercritical fluid extraction, microwave-assisted extraction, enzyme-assisted extraction, pulsed electric field treatment. These are characterized by shorter extraction times, lower amounts of solvent needed, the possibility to work at lower temperatures, and higher adaptability to automation, being therefore more green and sustainable methods.