The aim of this research was to investigate the phase equilibrium behavior of a system containing guacatonga extract + ethanol+ CO2 in order to help define the adequate conditions of temperature and pressure for the co-precipitation process, performed by means of supercritical anti-solvent (SAS) technique. Guacatonga (Casearia sylvestris) is a native medicinal plant from Brazil, rich invaluable components such as 13-caryophyllene, ez-humulene and bicyclogermacrene. Phase equilibrium data were obtained by the static method using guacatonga extract dissolved in ethanol (1:100, wt/wt), at temperatures ranging from 35 to 75 degrees C and CO2 mass content from 60 to 90 wt%. It was noticed that the system exhibited solid vapor liquid, solid liquid liquid and solid vapor liquid liquid transition types and a lower critical solution temperature behavior. Phase behavior study was considered for the definition of the SAS conditions applied for the encapsulation of guacatonga extract in the biopolymer Pluronic F127. The conditions tested ranged from 80 to 140 bar at 45 degrees C. At 80 bar only segregated particles of extract and the biopolymer were detected, while at 110 and 140 bar an extract encapsulation was achieved. (C) 2014 Elsevier B.V. All rights reserved.