Effects of entrainers on the purity of andrographolide extracted from andrographolide raw material by SC-CO2

The effects of the addition of non-toxic entrainers (ethanol, water, and acetic acid) in supercritical carbon dioxide (SC-CO2) extractions from andrographolide raw material were investigated. The extraction efficiency was improved by the addition of any of the three entrainers. Various temperatures (40, 55, and 70 °C) and pressures (8, 16, and 24 MPa) for the modified extraction processes were also compared. The highest purity was achieved at the highest temperature (70 °C) and highest pressure (24 MPa). For the three single entrainers, purities increased with increasing amounts (from 5% to 10%) of the entrainers. The highest purity was obtained with 10% acetic acid at 70 °C. SEM results showed that the crystal is the shortest and thinnest and XRD results showed that the highest crystallinity crystals were obtained when acetic acid was used as entrainer.