SUPERCRITICAL ANTISOLVENT (SAS) CO-PRECIPITATION OF ETHYL CELLULOSE AND NATURAL EXTRACTS IN SC-CO_2

摘要

The objective of this work has been the co-precipitation of the coating material Ethyl Cellulose (EC) and two natural extracts (IDOKI SCF Technologies), R1 and P1, using the Supercritical Antisolvent (SAS) precipitation technique with supercritical carbon dioxide (SC-CO_2), in order to obtain active microparticles. EC is a hydrophobic material widely used for controlled delivery systems, sustained release, drug packaging, long-acting formulations, taste masking or coatings. R1 and P1 natural extracts are characterized for their antioxidant/antimicrobial properties. For that purpose, a Thar SAS-50 vessel connected to a Thar R100 supercritical fluids system has been used to study different parameters: pressure, EC:extract, flow rate or solution concentration. The morphology and size of the microparticles were analyzed by scanning electron microscopy and the co-precipitation rate was quantified by S-L extraction and further chromatographic analysis. Agglomerated active EC microparticles (1-4μm) have been precipitated. AZTI-Tecnalia has evaluated their antimicrobial properties and GAIKER has checked their antioxidant activity.