New UHPLC Method for Cannabidiol Determination in Hard Capsules

Objectives: The aim of the study was to propose a new UHPLC method for the determination of cannabidiol (CBD) from supplements and drugs available on the Romanian market. Materials and methods: The HPLC assay of CBD was achieved by using a Phenomenex Gemini NX-C18 column. The mobile phase consisted of 70% acetonitrile and 30% water. Elution was performed in isocratic mode and the detection was done at 208 nm. The method was tested on hard capsules containing 150 mg of CBD.
Results and discussions: The retention time of CBD was 2.8 minutes. Regression analysis showed good linearity over the 1-100 ug/ml concentration range. The lowest limit of quantification was established at 1 µg/ml. The method was developed by using reconstituted capsules. The substance proved low stability in solution at room temperature and stability at temperatures between 2-8ºC. The recovery of reconstituted samples was 96.77%. The commercial capsules had a very low content of 15-20% from declared content.
Conclusions: The proposed method can be used for CBD determination in different pharmaceutical formulations – hard and soft capsules with coconut oil as excipient.