Optimization of Supercritical Extraction of Cannabidiol Using Response Surface Methodology

Hemp, also known as Cannabis sativa L., contains over 80 cannabinoids, with cannabidiol (CBD) being the primary neuroactive component. CBD possesses various pharmacological properties and is considered a non-psychoactive compound, making it a promising component for various applications, such as pharmaceuticals, cosmetics, and nutraceuticals. The aim of this study was to identify the optimal conditions for extracting CBD from hemp using supercritical fluid extraction (SFE). Response surface methodology (RSM) was employed to optimize the SFE conditions. The Box–Behnken design and the central composite design were utilized to refine the extraction parameters, including extraction time, temperature, and pressure. The statistical significance and reliability of the optimized conditions were confirmed by the significant influence of these independent variables on CBD yield. The extracted CBD was purified to a high level of purity and converted from cannabidiolic acid (CBDA) through heat treatment and then analyzed using high-performance liquid chromatography (HPLC). The following extraction conditions were considered optimal and led to a CBD yield of approximately 70.46 g/kg: pressure of 48.3 MPa, temperature of 60 °C, and extraction time of 109.2 min. Validation experiments confirmed the accuracy of the model, with experimental values closely matching the predicted values (69.93 ± 0.88 g/kg). This study demonstrates that SFE is an efficient method for obtaining high-purity CBD from hemp, highlighting its potential for industrial applications. The findings suggest that optimizing SFE conditions through RSM can significantly enhance the efficiency and yield of CBD extraction, providing a robust framework for industrial-scale production.