Lutein-loaded lipid-core nanocapsules: Physicochemical characterization and stability evaluation

Lutein nanocapsules (Lutein-LNC) were developed by the technique of interfacial deposition of the preformed polymer poly-epsilon-caprolactone (PCL). The lutein crystals were obtained from Marigold flowers by exhaustive extraction using tetrahydrofuran to the obtention of lutein 92% pure. The nanocapsules were prepared, characterized and their stability investigated. The results showed monomodal size distribution with a polydispersity index of 0.11 +/- 0.02, z-average of 191.9 +/- 3.24 nm, zeta potential of -5.14 +/- 2.22 mV and encapsulation efficiency of 99.51%. The physicochemical properties of polymeric nanocapsules suspension were evaluated in function of storage time to determine the formulation stability. After 60 days of storage (4 degrees C), the Lutein-LNC were stable without significant changes in diameter and color (p >= 0.05); and residual content of lutein was 36% relative to initial value. However, Lutein-LNC stored at 25 degrees C presented changes in zeta potential, pH, color values and residual content over time when compared to nanocapsules stored at 4 degrees C. Lutein content in the nanocapsules after 90 days of storage at 4 degrees C and 25 degrees C presented superior values than free lutein after 30 days of storage in same conditions. Thus, the nanoencapsulation allowed the solubilization of lutein in the aqueous medium and increased the stability of lutein in different temperatures. (C) 2017 Elsevier B.V. All rights reserved.