Solid-liquid extraction of andrographolide from plants-experimental study, kinetic reaction and model

Solid-liquid extraction is performed from leaves and stems of Andrographis paniculata in ethanol-water solvent, in order to obtain andrographolide. The first part of this work concerns the acquisition of the raw plant geometric and physicochemical characteristics. Then batch experiments are done in order to study the influences of the operating parameters (temperature, nature of the solvent and particles size). Furthermore, the destruction of the solute with high temperature is also studied. In the last part, an two-shape extraction model is proposed and compared with experimental data. This model includes the shape factor of the particles population composed of stems and leaves (cylinders and plates). (C) 2004 Elsevier B.V. All rights reserved.