Stability of cannabidiol, Δ9-tetrahydrocannabinol, and cannabinol under stress conditions

The aim of this work was to validate a high-performance liquid chromatography (HPLC) method for determination of the stability of cannabidiol, Delta(9)-tetrahydrocannabinol, and cannabinol. Furthermore, degradation kinetics were also investigated. Five stress conditions-acid degradation, alkaline degradation, oxidation, thermal degradation, and photodegradation-were evaluated. The results showed that the HPLC method had a linear response (R-2 >= 0.9999) in the test range of 1-200 mu g/mL. The method was specific, precise, and accurate. The limits of both detection and quantitation are also reported. According to the stress test, the three cannabinoids (cannabidiol, Delta(9)-tetrahydrocannabinol, cannabinol) were stable during exposure to a range of thermal conditions for 24 h. They were unstable when being subjected to acid conditions; cannabidiol under alkaline conditions was extremely unstable. Degradation kinetic analysis demonstrated that the compounds remained at a level of approximately 8% after 5 h, and approached a first-order reaction (R-2 = 0.9930) with a rate constant of - 0.5057 h(- 1). In summary, the obtained data can be used as a guide for the formulation development of cannabis products in order to maintain their active compounds as well as their activities.

Automated summary

The study validated an HPLC method for determining the stability of cannabidiol, Delta(9)-tetrahydrocannabinol, and cannabinol, as well as investigating their degradation kinetics. The results showed that the method had a linear response, specificity, accuracy, and reported detection and quantitation limits. Under various stress conditions, the cannabinoids exhibited different stabilities and degradation rates.