Antioxidants entrapment in polycaprolactone microparticles using supercritical assisted injection in a liquid antisolvent

In this work, the entrapment of two antioxidants, α-lipoic acid (ALA) and eugenol (EUG), in polycaprolactone (PCL) microparticles, using the supercritical assisted injection in a liquid antisolvent (SAILA), is proposed. Using SAILA, spherical and non-aggregated PCL particles, with average sizes between 0.2 and 1.2 μm, were produced. Then, coprecipitation experiments were performed: PCL/EUG and PCL/ALA particles with an average size of 0.99 ± 0.34 μm and 0.99 ± 0.18 μm, respectively, were produced, with entrapment efficiencies up to 90 %, considerably higher than results reported in the literature. EUG and ALA coprecipitates showed complete release kinetics in a maximum time of 2 days respect to dissolution time of about 4 h and 5 h of unprocessed EUG and ALA, respectively. Furthermore, the antioxidant power of the used compounds was preserved in the obtained co-precipitates.