Abstract: “Pithecellobium Jiringan (Jack) Prain (P.Jiringan) is one of the medicinal plant sources that consist of antioxidant compounds. The aim of this study was to investigate the effects of supercritical carbon dioxide (SC-CO2) extraction parameters on solubility and to determine the equilibrium constant of P.Jiringan oil in SC-CO2 and correlated the data with Chrastil and del Valle & Aguilera models. The experimental were conducted at temperatures ranging from 40 oC to 70 oC and pressure from 27.58 MPa to 44.82 MPa. The extraction duration was 60 minutes. The result shows the solubility of oil increased as the density of CO2 increased at constant temperature. The solubility experimental data correlated with both model was good agreement with more that 95% similarity where the Chrastil model was the best model correlated with the experimental data since the AARD% of Chrastil model (0.206%) is lowest compared to AARD% of del Valle and Aguilera model (0.5818). In addition, SC-CO2 give the highe”

Keywords: Equilibrium constant, Chrastil’s model, Pithecellobium Jiringan (Jack) Prain, Solubility, Supercritical fluid extraction