Chemical analysis and concentrations of cannabidiol substances used for refractory epilepsy in Chilean patients. An underestimated worldwide risk.

Objective: The purpose of this study is to analyze composition of HMS (homemade CBD), NLS (non-licensed commercial products), and bioequivalent CBD (BES) collected from Chilean patients that voluntary accepted to analyze the "CBD-substance."

Methods: Samples were collected through an open invitation for different patients to anonymously and free of charge participate in the analysis of CBD oil. The analysis of the active principle was performed using High-Resolution Liquid Chromatography (HPLC).

Results: A total of 35 samples were collected between March 2020 and September 2021, including two BES, six NLS, and 27 HMS products. The BES had an average CBD concentration of 89.15 mg/mL and an average THC concentration of 0.015 mg/mL, which complied with the maximum THC levels required by regulatory authorities (<0.2% THC.). The NLS (six samples) exhibited significant variability in CBD concentrations, ranging from a maximum of 78.5 mg/mL to a minimum of 0.1 mg/mL, with an average of 25.41 mg/mL. The THC concentrations ranged from 0 mg/mL to 2.43 mg/mL with an average of 0.62 mg/mL. The HMS products exhibited even higher variations of CBD concentrations, ranging from 0 to a maximum of 6.6 mg/mL. THC concentrations were even more variable, ranging from 0 mg/mL to 388 mg/mL.

Significance: The medical community and patients involved should be aware that Hemp products are not pure and/or innocuous. HMS are likely to have high levels of THC and very low CBD, far away from therapeutic doses of CBD. CBD used in epilepsy should be restricted to licensed products, especially in children where THC toxicity is much more harmful.

Plain Language Summary: The study analyzed three types of CBD (cannabidiol) oils: homemade, non-licensed, and bioequivalent. Homemade and non-licensed products showed nonacceptable variance of CBD and THC concentration (tetrahydrocannabinol), in some cases with 0 mgs of CBD and many beyond THC maximum accepted. The THC is another component found in cannabis and is responsible for the neurotoxic effects. Only bioequivalent products showed concentrations of CBD and THC acceptable for epilepsy treatment, therefore are the only products recommended for such purpose.