It is crucial to conduct quality control tests to assess the quality and consistency of medicinal plant products before they are used. Products can often be placed on the market without registration, but some countries may require manufacturers to present product labels to authorities before selling them. These labels should confirm the composition of the product, particularly the concentrations of cannabidiol (CBD). The information on the label should provide unambiguous details about the qualitative composition and concentration of primary cannabinoids, such as CBD and THC. However, since there is a lack of regulatory control, it is possible to find inaccurate information on the label. This study aimed to create and validate a high-performance liquid chromatography method for identifying active compounds (cannabinoids) in CBD oil. The main compounds identified included Cannabidivarin (CBDV), Cannabidiolic Acid (CBD-A), Cannabigerolic Acid (CBG-A), Cannabigerol (CBG), Cannabidiol (CBD), Tetrahydrocannabivarin (THCV), Cannabinol (CBN), ∆9- Tetrahydrocannabinol (d9 -THC) ∆8- Tetrahydrocannabinol (d8-THC), Cannabicyclol (CBL), Cannabichromene (CBC), and Tetrahydrocannabinolic Acid (THCA-A), determined in line with the International Conference on Harmonization's (ICH) guidelines. The method was validated for linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). It was determined to be linear, with a correlation coefficient (R2) ranging from 0.99937 to 0.99973. The LOD and LOQ values calculated from the calibration curve ranged from 0.05 to 0.13 and 0.50 to 0.61 µg/mL, respectively. The method also exhibited acceptable precision, with relative standard deviation values lower than or equal to 2%. The method's accuracy was assessed through recovery percentages and fell within an acceptable range (98.12–102.39%). This study's rigorous methodology and comprehensive findings significantly contribute to cannabinoid analysis. This validated protocol was used to analyze the cannabinoid concentration levels in 14 CBD oil products in the Republic of North Macedonia. The performance parameters indicate that the developed and validated method is suitable for quantitatively determining cannabinoids in CBD oil. The analysis of 14 CBD oil products revealed no significant derogation regarding the labeling, i.e., they were by the producers' declared variability.

The study highlights the need for quality control in evaluating medicinal plant products, especially CBD oils, before market release. Due to varying regulatory requirements, product labeling can sometimes be misleading, especially regarding cannabinoid concentrations such as CBD and THC. This research focused on developing a validated high-performance liquid chromatography (HPLC) method for accurately identifying and quantifying key cannabinoids in Commercial Veterinary CBD Oil. The main compounds identified included Cannabidivarin (CBDV), Cannabidiolic Acid (CBD-A), Cannabigerolic Acid (CBG-A), Cannabigerol (CBG), Cannabidiol (CBD), Tetrahydrocannabivarin (THCV), Cannabinol (CBN), ∆⁹-Tetrahydrocannabinol (d9-THC) ∆8-Tetrahydrocannabinol (d8-THC), Cannabicyclol (CBL), Cannabichromene (CBC), and Tetrahydrocannabinolic Acid (THCA), determined in line with the International Conference on Harmonization’s (ICH) guidelines. The method was validated for linearity, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ). It was determined to be linear, with a correlation coefficient (R²) > 0.999. The LOD and LOQ values calculated from the calibration curve ranged from 0.05 to 0.13 and 0.50 to 0.61 µg/mL, respectively. The method also exhibited acceptable precision, with relative standard deviation values lower than or equal to 2%. The method’s accuracy was assessed through recovery percentages and fell within an acceptable range of 98–102 if the RSD was 2%. This study’s rigorous methodology and comprehensive findings significantly contribute to cannabinoid analysis. This validated protocol was used to analyze cannabinoids in 14 commercial veterinary CBD oil products from the Republic of North Macedonia. The performance parameters demonstrated that the method is reliable for quantitatively measuring cannabinoids in CBD oil. The analysis showed that the cannabinoid levels in the products were consistent with the manufacturers’ declared specifications, with no significant discrepancies in labeling.