VALIDATION AND COMPARISON OF METHOD USING DIFFERENT WAVELENGTH DETECTION AT 210 AND 228 NM FOR QUANTITATIVE ANALYSIS OF CBD IN SUBLINGUAL CANNABIS OIL PRODUCTS

Abstract

Cannabidiol or CBD oil market is expected to grow 31.50% annually till 2030. Therefore, the method to accurately determine the quantity of CBD in oil products must be developed and validated. Various HPLC methods have been commonly developed with different ultraviolet (UV) wavelengths. In this research, we would like to compare new developed HPLC-UV method with isocratic elution using the wavelength of 210 nm, which is the maximal UV absorbance wavelength and 228 nm, which is recommended wavelength by previous work and Thai Pharmacopoeia to quantify CBD content based on ICH guidelines. Specificity, accuracy, precision, linearity, range, limit of detection (LOD) and limit of quantitation (LOQ) were evaluated. It was found that both methods exhibited a good linear relationship of CBD with R2 equal to 0.9997. Per cent of RSD from both methods were less than 2%, and the mean %recovery was in the range of 99-100%. LOD and LOQ for the 210 nm method were 5.93 and 17.96 µg/ml, respectively and for the 228 nm, LOD and LOQ were 5.77 and 17.49 µg/ml.  It can be concluded that both methods were suitable for the analysis of CBD content in oil formulations, and no significant difference (p>0.05) between both methods was found. Additionally, these methods were used to analyse CBD content from sublingual oil formulations which contain 50 and 100 mg/g of CBD. Percent labelled amount of CBD in CBD sublingual oil has complied with the criteria of Thai Pharmacopoeia. Our developed method was verified to be accurate and simple without the tedious procedure of sample preparation.