Constituents of cannabidiol products

Abstract

Cannabinoids have therapeutic and medicinal properties. The two main cannabinoids found in the cannabis plant are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Different cannabis-based preparations with varying concentrations of ∆-9 THC are available on the market. There is a need for efficient analytical methods to determine concentrations of THC in CBD oils to ensure that THC content does not exceed allowable limits of 0.2-0.3%. The aim of the study was to develop and validate an analytical method for the determination of tetrahydrocannabinol (THC) in cannabidiol (CBD) oil. The study was conducted at the Pharmaceutical Synthesis and Technology laboratory at the Department of Pharmacy, University of Malta. Methods of sample preparation were compared to determine which will give the best results in terms of area under the peak (AUP) and reproducibility of peak for THC: (1) Solvent extraction (2) Dilute and Shoot and (3) Extraction using Agilent Captiva EMR-lipid kit. Analysis of THC in oil was conducted using Agilent 1260 Infinity Series®II Liquid Chromatography System with ultra-violet (UV) Detection at 225 and 275 nm. Separation was carried out on an InfinityLab Poroshell 120 EC-C18 Column 2.7 µm (3.0 x150mm) at 40°C using acetonitrile and 85% ortho-phosphoric acid (65:35 v/v) as the mobile phase at a flow rate of 1ml/min. Method was validated according to International Council on Harmonisation guidelines. THC in oil was prepared for analysis by dilution in methanol (1:500). Peak for THC had a retention time of 9.81 minutes. The method had acceptable intra-day precision with relative standard deviation values ranging between 0.61 and 11.2% and acceptable linearity (r2=0.9909). Method was successfully applied to determine concentrations of THC in commercially available CBD oil. The use of an efficient method of analysis for determination of cannabinoid concentrations in cannabis-based products is important to ensure quality, safety, and efficacy of cannabis-based products.