Ultrasound-Assisted Extraction of Cannabinoids from Cannabis Sativa for Medicinal Purpose

Over the past twenty years, the interest on Cannabis oily extracts for medicinal use compounded in pharmacy has been considerably grown up along with the need in having preparations of adequate quality. Hot maceration (M) is the most frequently used method to compound oily solutions. In this work, we systematically studied the possibility to use an ultrasonic homogenizer and a sonotrode (US) as an alternative extraction method. Oily solutions were prepared using two available varieties of Cannabis for medicinal use, called FM2 and Bedrocan. All preparations resulted with an equiv-alent content in CBD and THC, with the advantage of a faster process using US. In particular, 10 min sonication at the amplitude optimized for the sonotrode used (2 or 7 mm) provides not statis-tically different total Δ9-tetrahydrocannabinol (M-FM2: 0.26±0.02 %w/w; US-FM2: 0.19±0.004 %w/w; M-Bedrocan: 1.83±0.17 %w/w; US-Bedrocan: 1.98±0.01 %w/w) and total cannabidiol (M-FM2: 0.59±0.04 %w/w; US-FM2: 0.58±0.01 %w/w) amounts extracted in refined olive oil. It can therefore be confirmed that sonotrode is an efficient and fast extraction technique and their use is without negative consequence on the solvent properties. Despite DSC evidenced that both macer-ation and sonication modify the Tonset and enthalpy of the event at about -10° C, the qualitative characteristics of the oil remained constant for the two treatments and similar to the starting material.