Andrographis paniculata extracts were precipitated using the so-called supercritical antisolvent (SAS)
technique. Ethanol was used as the solvent and compressed CO2 as the antisolvent. The effects of process
operating conditions (pressure: 5–24 MPa, temperature: 308–328 K and CO2 flow rate: 0.5–1.5 g/min) on
particle size and morphology of precipitated andrographolide were evaluated. X-ray diffraction (XRD)
patterns showed significant changes in andrographolide morphology depending on process operating
conditions; both column-like and slice-like crystals were observed depending on operating conditions.
Crystals with mean diameters of 3.30–228.35 μm were produced, smaller crystals were obtained at high
pressure, low temperature and high CO2 flow rate and vice versa for large crystals. In addition, SAS process
also produced high precipitation yields, since solubility of andrographolide is small in the supercritical CO2
plus ethanol. When operating under subcritical conditions, amorphous particles were produced.