Pharmacokinetics of cannabichromene in a medical cannabis product also containing cannabidiol and Δ(9)-tetrahydrocannabinol: a pilot study

PURPOSE: Cannabichromene (CBC) is a phytocannabinoid commonly found in cannabis, yet its acute post-dose pharmacokinetics (PK) have not been examined in humans. This is a secondary data analysis from a trial investigating Spectrum Yellow oil, an oral cannabis product used for medical purposes that contained 20 mg cannabidiol (CBD), 0.9 mg Δ(9)-tetrahydrocannabinol (THC), and 1.1 mg CBC, per 1 mL of oil. METHODS: Participants (N = 43) were randomized to one of 5 groups: 120 mg CBD, 5.4 mg THC, and 6.6 mg CBC daily; 240 mg CBD, 10.8 mg THC, and 13.2 mg CBC daily; 360 mg CBD, 16.2 mg THC, and 19.8 mg CBC daily; 480 mg CBD, 21.6 mg THC, and 26.4 mg CBC daily; or placebo. Study medication was administered every 12 h for 7 days. Plasma CBC concentrations were analyzed by a validated two-dimensional high-performance liquid chromatography–tandem mass spectrometry assay. RESULTS: After a single dose and after the final dose, the C(max) of CBC increased by 1.3–1.8-fold for each twofold increase in dose; the t(max) range was 1.6–4.3 h. Based on the ratio of administered CBD, THC, and CBC to the plasma concentration, the dose of CBD was 18 times higher than the dose of CBC, yet the AUC(0–t) of CBD was only 6.6–9.8-fold higher than the AUC(0–t) of CBC; the dose of THC was similar to the dose of CBC, yet THC was quantifiable in fewer plasma samples than was CBC. CONCLUSIONS: CBC may have preferential absorption over CBD and THC when administered together. Trial Registration: Australian New Zealand Clinical Trials Registry #ACTRN12619001450101, registered 18 October 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00228-021-03232-8.