Centrifugal partition chromatography for purification of Cannabidiol from Cannabis sativa

The Cannabis sativa plant is rapidly gaining in popularity because of the medicinal application of the non-psychotropic component, cannabidiol (CBD), which can aid in treatment of conditions including: pain, inflammation, epilepsy, and cancer. Interest in the purification, formulation, and detection of CBD has increased rapidly due to the recent changes in the legal status of cannabis compounds for medicinal use. As a result, Gilson has developed a rapid and reproducible method for large-scale purification of CBD using the liquid-liquid chromatography technique, centrifugal partition chromatography (CPC). A liquid stationary phase is retained inside the CPC column by a centrifugal field while a non-miscible liquid is pumped through as the eluent. The separation of components in the sample is dependent on the phase volume ratio inside the column and the partition coefficient of the solutes in both phases. The CPC can be operated in one of two modes for a particular run: ascending or descending, in which the CPC column is operating in normal or reversed phase. Following elution of compounds in the mobile phase, the solvents on the CPC column are replaced during the extrusion step in which stationary phase is loaded onto the CPC column, displacing remaining solvent and separated compounds, which can be optionally collected as fractions. A CPC 250 PRO column was controlled by a PLC 2250 Purification System equipped with a quaternary gradient pump, UV/VIS detector, fraction collector, and Gilson Glider CPC software.

5 g of crude C. sativa extract were subjected to purification by CPC in which 205 mg of CBD were purified to over 95% as shown by HPLC analysis. For each 5 g of sample, 1 L of solvent was consumed for every 10 minutes of separation. Purification parameters can be adjusted to target specified cannabinoids of interest and the method can be adapted from milligram to multi-kilogram scale providing reliable purifications for all industries.