Deposition of CAP/Antioxidants Systems on Silica Particles Using the Supercritical Antisolvent Process

Supercritical carbon dioxide has been used to deposit co-precipitates of natural antioxidants with a polymer onto silica microparticles. The supercritical antisolvent process (SAS) was carried out with the antioxidants by introducing the silica microparticles into the precipitator vessel. Two different configurations were employed to pump the solution. In one configuration, the antioxidant and the polymer were dissolved and injected together through a nozzle. In the second configuration, the antioxidant and the polymer were dissolved in different solutions and sprayed through different nozzles. The use of operating conditions significantly above the critical point (180 bar and 323 K) led to the formation of composites made up of co-precipitates and silica. Delivery profiles showed that the presence of the polymer and the silica delayed release of the antioxidant into gastric media, thus protecting it and allowing its full delivery to the intestinal fluids to improve the effectiveness of the antioxidant.