Technical optimization of the extraction of andrographolide by supercritical CO2

An experimental design has been built in order to study the influence of different parameters on the crystallization ratio and purity of andrographolide extraction using supercritical CO2: pressure (8–24 MPa), temperature (40–70 °C) and extraction duration (45–105 min). Crystallization ratios are between 14.32 and 72.29 wt%, and purities are between 43.11 and 79.78 wt%, indicating that the experimental design covers a large range of results. The results indicate that pressure and extraction duration are the most influencing parameters.