Production of natural carotene-dispersed polymer microparticles by SEDS-PA co-precipitation

In this work, composite microparticles of poly (ethylene glycol) (PEG) loaded with natural carotene were successfully produced using solution enhanced dispersion by supercritical fluids through prefilming atomization (SEDS-PA) process. The characteristics of dispersion of carotene in the polymeric drug carrier were analyzed by color difference between carotene and PEG using optical micrographs. The morphologies and particle sizes (PSs) of the composite microparticles were studied by SEM micrographs. The precipitates were amorphous particles of PEG embedded with flake-like natural carotene crystals. The carotene degradation of the carotene/PEG composite microparticles was substantially lessened under the protection of PEG carrier in comparison with that of carotene microparticles. With the increase of the carotene content added in solution, the PSs of carotene crystals dispersed into the PEG carrier increase, the carotene loading yields in the composite microparticles (Wc2) obviously increased, whereas PSs of these composite particles slightly decreased. Higher operating temperature resulted in formation of bigger coalesced composite particles and the substantial increase of Wc2. With increase of operating pressure PSs decreased, whereas no clear dependence of Wc2 was obtained on it