Cannabidiol, ∆9-tetrahydrocannabinol, and metabolites in human blood by volumetric absorptive microsampling and LC-MS/MS following controlled administration in epilepsy patients

• Published in: Frontiers in pharmacology 2022-10, Vol.13, p.1038754-1038754
• Main Authors: Pigliasco, Federica, Malaca, Sara, Lo Faro, Alfredo Fabrizio, Tini, Anastasio, Cangemi, Giuliana, Cafaro, Alessia, Barco, Sebastiano, Riva, Antonella, Pisati, Angelica, Amadori, Elisabetta, Striano, Pasquale, Tagliabracci, Adriano, Huestis, Marilyn Ann, Busardò, Francesco Paolo
• Format: Article
• Language: English
• Subjects: cannabinoids; CBD metabolites; medical cannabis; Pharmacology; serum; UHPLC-MS/MS
• ISSN: 1663-9812; 1663-9812
• DOI: 10.3389/fphar.2022.1038754

Cannabidiol (CBD) exhibits anti-inflammatory, anxiolytic, antiseizure, and neuroprotective proprieties without addictive or psychotropic side effects, as opposed to Δ 9 -tetrahydrocannabinol (THC). While recreational cannabis contains higher THC and lower CBD concentrations, medical cannabis contains THC and CBD in different ratios, along with minor phytocannabinoids, terpenes, flavonoids and other chemicals. A volumetric absorptive microsampling (VAMS) method combined with ultra-high-performance liquid chromatography coupled with mass spectrometry in tandem for quantification of CBD, THC and their respective metabolites: cannabidiol-7-oic acid (7-COOH-CBD); 7-hydroxy-cannabidiol (7-OH-CBD); 6-alpha-hydroxy-cannabidiol (6-α-OH-CBD); and 6-beta-hydroxycannabidiol (6-β-OH-CBD); 11- Hydroxy-Δ 9 -tetrahydrocannabinol (11-OH-THC) and 11-Nor-9-carboxy-Δ 9 -tetrahydrocannabinol (THCCOOH). After overnight enzymatic glucuronide hydrolysis at 37°C, samples underwent acidic along with basic liquid-liquid extraction with hexane: ethyl acetate (9:1, v/v). Chromatographic separation was carried out on a C18 column, with the mass spectrometer operated in multiple reaction monitoring mode and negative electrospray ionization. Seven patients with intractable epilepsy were dosed with various CBD-containing formulations and blood collected just before their daily morning administration. The method was validated following international guidelines in toxicology. Linear ranges were (ng/ml) 0.5–25 THC, 11-OH-THC, THCCOOH, 6-α-OH-CBD and 6-β-OH-CBD; 10–500 CBD and 7-OH-CBD; and 20–5000 7-COOH-CBD. 7-COOH-CBD was present in the highest concentrations, followed by 7-OH-CBD and CBD. This analytical method is useful for investigating CBD, THC and their major metabolites in epilepsy patients treated with CBD preparations employing a minimally invasive microsampling technique requiring only 30 µL blood.