Influence of entrainers on supercritical CO₂ extracting and crystallizing andrographolide

The experimental materials of 30% and 95% andrographolide were chosen to investigate the influence of entrainers, including ethanol, acetone, petrohol and ethylacetate on the crystallization ratio, purity, crystal surface and crystal configuration during supercritical carbon dioxide extraction and crystallization. The results show that ethylacetate is the best entrainer which compositive effects on separation and purification of andrographolide are the best. Moreover, it can realize the unification of extraction solvent in the preceding procedure and entrainer, and eliminate the pollution between solvents, the quality of andrographolide crystal cooperated with ethylacetate entrainer is better.