Micronized dry emulsion with solid nanocore: A novel strategy to incorporate a large amount of ceramides

Conventional oil-in-water or water-in-oil emulsions that serve as carriers for drugs and other hydrophobic substances eventually break down and undergo phase separation, coalescence, creaming, and/or flocculation. To overcome this issue, we fabricated dry emulsions with solid cores that can encapsulate high amount of ceramides with high hydrophobicity (logP>9) via spray drying. Based on pseudo-ternary diagrams of 50 formulations, 5 nanoemulsions with an optimum particle size (∼200 nm) and good storage stability (4 weeks) were selected and used to fabricate core-shell-type dry emulsions with ceramides (cDEs). These cDEs were microsized spheres and incorporated 15-23 % (w/w) of ceramides in emulsions. The solid-core cDEs 5 and 6 well-reconstituted in water, presented good colloidal stability with low polydispersity (PDI<0.15), and were smaller than those of DEs with liquid cores. Moreover, the selected DEs exhibited particle sizes of 4–7 μm and reconstituted to a submicron size. We believe that our cDEs could be a tool to encapsulate poorly soluble ceramides and other insoluble bioactive compounds in commercial products.