Center for Forensic Science Advancement and Application, RTI International, 3040 East Cornwallis Rd, Research Triangle Park, NC 27709, USA.
Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr., Baltimore, MD 21224, USA.
J Anal Toxicol. 2023 Sep 15;47(7):632-635. doi: 10.1093/jat/bkad043.
Cannabidiol (CBD) has been shown to convert to ∆9-tetrahydrocannabinol (∆9-THC) in acidic environments, raising a concern of conversion when exposed to gastric fluid after consumption. Using synthetic gastric fluid (SGF), it has been demonstrated that the conversion requires surfactants, such as sodium dodecyl sulfate (SDS), due to limited solubility of CBD. Recently, water-compatible nanoemulsions of CBD have been prepared as a means of fortifying beverages and water-based foods with CBD. Since these emulsions contain surfactants as part of their formulation, it is possible that these preparations might enhance the production of ∆9-THC even in the absence of added surfactants. Three THC-free CBD products, an oil, an anhydrous powder and a water-soluble formulation, were incubated for 3 h in SGF without SDS. The water-soluble CBD product produced a dispersion, while the powder and the oil did not mix with the SGF. No THC was detected with the CBD oil (<0.0006% conversion), and up to 0.063% and 0.0045% conversion to ∆9-THC was observed with the water-soluble CBD and the CBD powder, respectively. No formation of ∆8-THC was observed. In comparison, when the nano-formulated CBD was incubated in SGF with 1% SDS, 33-36% conversion to ∆9-THC was observed. Even though the rate of conversion with the water-soluble CBD was at least 100-fold higher compared to the CBD oil, it was still smaller than ∆9-THC levels reported in CBD products labeled "THC-free" or "<0.3% THC" based on the Agricultural Improvement Act of 2018 (the Farm Bill). Assuming a daily CBD dose of around 30 mg/day, it is unlikely that conversion of CBD to ∆9-THC could produce a positive urinary drug test for 11-Nor-9-carboxy-∆9-THC (15 ng/mL cut-off).
大麻二酚（CBD）在酸性环境下会转化为 ∆9-四氢大麻酚（∆9-THC），因此人们担心摄入后会在胃中与胃液接触而发生转化。使用人工胃液（SGF）已经证明，这种转化需要表面活性剂，如十二烷基硫酸钠（SDS），因为 CBD 的溶解度有限。最近，已经制备了水溶性 CBD 纳米乳剂作为向饮料和水基食品中添加 CBD 的方法。由于这些乳液作为其配方的一部分含有表面活性剂，因此即使没有添加表面活性剂，这些制剂也有可能增强 ∆9-THC 的生成。将三种不含 THC 的 CBD 产品，即油、无水粉末和水溶性制剂，在不含 SDS 的 SGF 中孵育 3 小时。水溶性 CBD 产品产生了分散体，而粉末和油则与 SGF 不混合。用 CBD 油未检测到 THC（<0.0006%转化率），而水溶性 CBD 和 CBD 粉末分别观察到高达 0.063%和 0.0045%的 ∆9-THC 转化率。未观察到 ∆8-THC 的形成。相比之下，当纳米配方的 CBD 在含有 1% SDS 的 SGF 中孵育时，观察到 33-36%的 ∆9-THC 转化率。尽管水溶性 CBD 的转化率至少比 CBD 油高 100 倍，但仍低于根据 2018 年《农业改进法案》（《农场法案》）标记为“不含 THC”或“<0.3% THC”的 CBD 产品报告的 ∆9-THC 水平。假设每天摄入 CBD 剂量约为 30 毫克，CBD 转化为 ∆9-THC 不太可能导致尿液药物检测呈阳性，用于检测 11-去甲-9-羧基-∆9-THC（15ng/mL 截止值）。
