Seabuckthorn (Hippophae rhamnoids L) seed oil having high nutraceutical, cosmeceutical and therapeutic activity has been extracted from dried seabuckthorn (SBT) seed powder using supercritical carbon dioxide (SC-CO(2)). The solubility parameter of SBT actives (tocopherols, lycopene and beta-carotene), CO(2), and entrainer solvents was calculated and validated with experimental results. The free radical scavenging activity of the extract was evaluated in terms of DPPH. assay. Theoretically, pressure and temperature had significant effect on extraction of SBT actives. A maximum recovery of 77.2% tocopherol, 75.5% carotene and an EC(50) of 49.9 mg/mL (from DPPH. assay) was obtained after SC-CO(2) extraction at 35 degrees C, 400 bar and run time of 60 min. Further optimization of the extraction conditions by Box-Behnken design increased the extraction efficiency. Use of 2-propanol as an entrainer at 30% v/w of dried SBT seed powder at optimized conditions showed a recovery of tocopherols and carotenes of 91.1% and 69.6%, respectively, while it showed EC(50) of 38.9 mg/mL. The optimized conditions were a temperature of 35 degrees C, pressure of 305 bar and run time of 90 min. (C) 2011 Elsevier B.V. All rights reserved.