Background and objectives: A wide variety of products containing cannabidiol (CBD) are available on the commercial market. One of the most common products, CBD oil, is administered to self-treat a variety of conditions. These oils are available as CBD isolate, broad-spectrum [all terpenes and minor cannabinoids except Δ-9-tetrahydrocannabinol (THC)], or full-spectrum (all terpenes and minor cannabinoids with THC < 0.3% dried weight) products. A systematic pharmacokinetic study was performed to determine whether there are differences in the pharmacokinetic parameters and systemic exposure of CBD after oral dosing as an isolate, broad-spectrum, or full-spectrum product.
Methods: Male and female Sprague Dawley rats were treated with a single, equivalent oral dose of CBD delivered as isolate, broad-spectrum, or full-spectrum product. An additional study using an in-house preparation of CBD isolate plus 0.2% THC was performed. A permeability assay was also conducted to investigate whether the presence of THC alters the intestinal permeability of CBD.
Results: There was an increase in the oral bioavailability of CBD (12% and 21% in male and female rats, respectively) when administered as a full-spectrum product compared with the isolate and broad-spectrum products. There was no difference in the bioavailability of CBD between the commercially available full-spectrum formulation (3.1% CBD; containing 0.2% THC plus terpenes and other minor cannabinoids) versus the in-house preparation of CBD full-spectrum (CBD isolate 3.2% plus 0.2% THC isolate). In vitro permeability assays demonstrated that the presence of THC increases permeability of CBD while also decreasing efflux through the gut wall.
Conclusions: The presence of 0.2% THC increased the oral bioavailability of CBD in male and female rats, indicating that full-spectrum products may produce increased effectiveness of CBD due to a greater exposure available systemically.
© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.