Cannabidiol in Icelandic grown hemp: Extraction methods and analytical techniques

Abstract

The use of cannabis in traditional medicine has roots in Ayurveda and ancient Chinese medicinal texts. Recently, the medicinal properties of cannabinoids found in cannabis plants have drawn attention, leading to the development of medicinal products, at least two of which are currently registered in Europe. One of these products, Sativex®, contains a mixture of the two main cannabinoids tetrahydrocannabinol (THC) and cannabidiol (CBD) and is used in adults with multiple sclerosis. The other, Epidyolex® is a pure CBD product, used to treat patients over two years of age with rare forms of epilepsy conditions.The study aims to develop a method for extraction of cannabidiol from industrial hemp grown in Iceland as well as a robust UPLC-UV method for the analysis and quantification of CBD in the extracts. Both methanol and ethanol extracts were prepared and the difference of concentration in the extracts were analyzed as well as the difference of CBD concentration in flowers and leaves. A method was also tested with the aim of increasing the concentration of CBD in the extract by doing a cold extract followed by a liquid-liquid acid-base partition.The analysis revealed that methanol extraction offers a significantly higher concentration of CBD than an ethanol extraction. The results also showed a clear difference between the flowers and leaves, with the flowers exhibiting a markedly higher concentration of CBD. The cold extraction followed by acid-base partition showed promising results with a high concentration of CBD within the more processed extract. The presence of other cannabinoids was confirmed in the methanol extract using UPLC-MS. This study contributes to the development of CBD extraction methods by highlighting the importance of the method of extraction and which plant part is used for extraction.