Abstract
The solubilities of two different non-psychoactive cannabinoids i.e., cannabigerol (CBG) and cannabidiol (CBD), in supercritical carbon dioxide (CO(2)) have been determined at 315, 326 and 334 K and in the pressure range from 11.3 to 20.6 MPa. These solubility data have been compared to the previously determined solubilities of two psychoactive cannabinoids i.e., (-)-Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and cannabinol (CBN), in supercritical CO(2). An analytical method with a quasi-flow apparatus was used for the experimental determination. Within the investigated temperature and pressure range, the molar solubility of CBG ranged from 1.17 to 1.91 x 10(-4) and the molar solubility of CBD ranged from 0.88 to 2.69 x 10(-4). The solubility of the different cannabinoids in supercritical CO(2) increases at 326 K in the following order: Delta(9)-THC < CBG < CBD < CBN. The solubility data were correlated using the Peng-Robinson equation of state in combination with Van der Waals mixing rules. Deviations between calculated results and the experimental data ranged from 0.81 to 6.35% absolute average relative deviation (AARD), except for CBD at 334 K, where the AARD was 18.4%. (C) 2010 Elsevier B.V. All rights reserved.