Modelling of andrographolide extraction from andrographis paniculata leaves in a soxhlet extractor

Andrographolide is the main diterpenoid lactone contained in the leaves of Andrographis paniculata. This bioactive component has multifunctional medicinal properties such as activity against fever, dysentery, diarrhoea, inflammation, and sore throat as well as immune disorder. To date, extraction of andrographolide from Andrographis paniculata is usually carried out using liquid organic solvent.The extraction was carried out by employing methanol as solvent using standard soxhlet method. Five grams of ground-dried Andrographis paniculata leaves was extracted using 1.50 × 10-4 m3 of methanol at different extraction times. The crude methanolic extracts were then analysed their andrographolide content using high performance liquid chromatography. A mathematical model based on rapid mass transfer at the interphase of the solid-liquid surface and introduction of volumetric mass transfer coefficient has been developed to describe the extraction phenomena. The final form of the model is Es = 0.12 × (1- e-1.69E-04 t), where Es = total extract, (g) and t = extraction time, (second). The model showed good agreement with the experimental data by generating AARD of about 0.46 %.