Cannabidiol (CBD), together with its precursor cannabidiolic acid (CBDA), is the major phytocannabinoid occurring in most hemp cultivars. To ensure the safe use of these compounds, their effective isolation from hemp extract is required, with special emphasis on the elimination of ∆⁹-tetrahydrocannabinol (∆⁹-THC) and ∆⁹-tetrahydrocannabinolic acid (∆⁹-THCA-A). In this study, we demonstrate the applicability of fast centrifugal partition chromatography (FCPC) as a challenging format of counter-current preparative chromatography for the isolation of CBD and CBDA free of psychotropic compounds that may occur in Cannabis sativa L. plant extracts. Thirty-eight solvent mixtures were tested to identify a suitable two-phase system for this purpose. Based on the measured partition coefficients (K_D) and separation factors (α), the two-phase system consisting of n-heptane:ethyl acetate:ethanol:water (1.5:0.5:1.5:0.5; v:v:v:v) was selected as an optimal solvent mixture. Employing UHPLC-HRMS/MS for target analysis of collected fractions, the elution profiles of 17 most common phytocannabinoids were determined. Under experimental conditions, the purity of isolated CBD and CBDA was 98.9 and 95.1% (w/w), respectively. Neither of ∆⁹-THC nor of ∆⁹-THCA-A were present; only trace amounts of other biologically active compounds contained in hemp extract were detected by screening against in-house spectral library using UHPLC-HRMS. Graphical abstract

Cannabidiol (CBD), a phytocannabinoid commonly isolated from chemotype III Cannabis sativa plants, is known for its therapeutic potential. However, comprehensive information on its bioavailability is still lacking. The key objective of this study was to investigate the impact of specific formulations on CBD delivery to the site of action and, in particular, the brain of experimental animals. As brain tissue is an extremely complex matrix, a highly sensitive method employing liquid chromatography–tandem mass spectrometry (LC-MS/MS) had to be implemented. To make it applicable for multiple analytes, the method was validated for 17 other phytocannabinoids and selected metabolites. Using this method, a pharmacokinetic study was conducted on 200 brain samples collected from rats that had been administered various CBD formulations (carriers) via oral gavage. The peak concentration in brain occurred within 1–2 h; notably, the highest was reached with carriers containing triacylglycerols with the shortest fatty acid chains (caprylic/capric). In addition to the parent compound, 7-hydroxy-cannabidiol and 7-carboxy-cannabidiol were detected, confirming rapid post-administration metabolism. Overall, this research enhances understanding of CBD distribution in the brain and underscores the impact of specific formulations on its bioavailability, offering insights into optimizing CBD-based therapies to be both effective and ‘patient-friendly’.