Experimental and Modelling Studies of Andrographolide Extraction from Andrographis Paniculata

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. The objectives of this work were to study the effect of polarity and Hildebrand solubility parameter of solvents in the extraction of andrographolide from A. paniculata and to develop a mathematical model to quantitatively describe the extraction phenomena. The extraction was carried out by employing various organic solvents and their mixtures with water as solvents using standard soxhlet method. Five grams of ground - dried A. paniculata leaves was extracted using 1.00 x 10 -4 m3 of solvent for 80minutes. The standard soxhlet extraction method was conducted using methanol, ethanol, ethyl acetate and water at different extraction times to verify the mathematical model proposed in this work. Methanol was found to be the best solvent for the extraction of andrographolide from A. paniculata . The Hildebrand solubility parameter concept was not able to predict the extraction of andrographolide using polar organic solvents. The final form of the proposed model based on rapid mass transfer at the interphase of the solid-liquid surface and the introduction of volumetric mass transfer coefficient is Es = 0.8917t – 9.8114 , where ,Es = total extract (g) and t = extraction time (in minutes).