Poly(ε-caprolactone) electrospun nanofibers containing cinnamon essential oil nanocapsules: A promising technique for controlled release and high solubility

Nowadays, cinnamon essential oil is one of the most popular spices for food flavoring and also for medicinal uses such as anti-inflammation agent, but its low solubility, irritations, and allergic reactions limit its applications. To overcome these limitations, cinnamon essential oil-loaded nanocontainers were prepared via inclusion complexation between the cyclodextrins and cinnamon essential oil under two different conditions, i.e., at room temperature or under sonic energy. The resulting supramolecular nanocontainers were characterized by XRD, SEM, DSC, and FTIR. Successful insertion of cinnamon essential oil in the cyclodextrins' cavity was confirmed by the significant differences between the FTIR, DSC, and XRD spectra of initial mixtures and those of the complexes. XRD results indicated that crystalline complexes adopted a mixture of head to head channel-type and cage conformation for cinnamon essential oil/cyclodextrins at various conditions. Solubility, bioavailability, and in vitro dissolution of obtained cinnamon essential oil nanocapsules were investigated, and results show that by encapsulation of cinnamon essential oil, solubility improved and its release is controllable. The solubility of cinnamon essential oil increased linearly as the concentration of cyclodextrins was increased, confirming the 1:1 stoichiometry of the complex. Electro-spun nanofibers of poly-e-caprolactone containing cinnamon essential oil/cyclodextrins inclusion complex at various conditions indicated that these nanofibers did not show beading defect with controlled release of cinnamon essential oil.