An improved method for the determination of cannabidiol in topical products using ultrasound-assisted extraction and gas chromatography-mass spectrometry

The recent surge in the sale of cannabidiol (CBD)-based topicals has risen rapidly in recent years, as it can be used to treat a multitude of skin disorders. However, there is minimal regulation concerning actual CBD content in these products. Topicals on the market may contain various concentrations of CBD and may be combined with a range of other compounds. The concentration of CBD has to be determined before the products enter the market. For this reason, a selective analytical method was developed using a 23 factorial design; and validated to determine CBD content in various topicals based on ultrasound-assisted extraction (UAE) followed by gas chromatography coupled to mass spectrometry (GC-MS). The method showed good precision (relative standard deviation ≤ 7.7%), accuracy at three concentration levels (recovery > 97.9%) for three different matrices, acceptable linearity (R2 > 0.99), and limit of detection (0.05 µg/mg). The method was successfully applied to the analysis of five commercial topicals. The proposed method is rapid, sensitive, precise, and accurate. In addition, it does not require derivatization and it is suitable for the determination of CBD in topicals for quality control purposes. •An analytical method to determine cannabidiol (CBD) in topicals was developed.•Ultrasound-assisted extraction was used as sample preparation followed by GC-MS.•Experimental design was applied to achieve the optimal method conditions.•The method was validated over the range of 0.08–15.79 μg/mg.•Five commercial topicals with different CBD content and composition were analyzed.