Development and Validation of a Simple, Fast, and Accessible HPLC-UV Method for Cannabinoids Determination in Cannabis sativa L. Extracts and Medicinal Oils

Abstract

Introduction: Cannabis sativa L. is a well-recognized medicinal plant. Cannabis regulations in Argentina are insufficient to solve the problem of patient access to full-spectrum cannabis-based products. So, the market of artisanal products with unknown quality and dosage of cannabinoids is increasing, and so is the local demand and need for analyzing these products. However, much of the latest validated methodologies for cannabinoid quantification include expensive instrumentation that is not always available in laboratories of health institutions in Argentina. Methods: The aim of this work was to develop and validate a simple and rapid HPLC-UV method for the identification and quantification of principal cannabinoids in cannabis resins, inflorescences, and medicinal oils using standard HPLC equipment. The cannabinoids selected for validation were cannabidiol acid (CBDA), cannabigerol (CBG), cannabidiol (CBD), cannabinol (CBN), delta-9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), and tetrahydrocannabinol acid (THCA). A method for the simultaneous identification and quantification of these 7 main cannabinoids was developed and then validated. Some data parameters were comparable to other reports with more sophisticated analytical instruments for the analysis of cannabis. The assessed limits of detection and the limits of quantitation ranged from 0.9 to 3.66 μg/mL and 2.78 to 11.09 μg/mL, respectively. The concentration-response relationship of the method indicated a linear relationship between the concentration and peak area with R2 values of > 0.99 for all 7 cannabinoids. Results: The relative standard deviation (RSD%) varied from 2.34 to 4.82 for intraday repeatability and from 1.16 to 3.15 for interday repeatability. The percentage of recovery values was between 94 to 115% (resins) and 80 to 103% (inflorescence extract). The cannabis industry is growing rapidly, and there is a need for reliable testing methods to ensure the safety and efficacy of cannabis products. In addition, current methods for cannabinoid analysis are often time-consuming and expensive, while the HPLC-UV method herein reported is a simple, rapid, accurate, and cost-effective alternative for the analysis of cannabinoids in cannabis resins, inflorescences, and medicinal oils. Conclusion: This method will be proposed to be included in the Cannabis sativa L. monograph of the Argentine Pharmacopoeia.