The aim of the study is the evaluation of the impact of glyceryl ester surfactants on cell permeating properties of SEDDS (self-emulsifying drug delivery systems).
Methods
SEDDS containing the glyceryl ester surfactants polyglyceryl-3-stearate (TGlysurf9), polyglyceryl-5-oleate (TGlysurf11.5) and glyceryl stearate citrate (TGlysurf12) were prepared and characterized regarding droplet size and zeta potential. Toxicity studies were performed on Caco-2 cells using resazuring assay. The formulations were loaded with fluorescein diacetate (FDA) and curcumin, and cell uptake studies on Caco-2 cells were performed. Cell uptake was visualized via real time live confocal microscopy. Cell permeability of the SEDDS was tested and trans-epithelial electrical resistance (TEER) measurements were performed. Furthermore, the anti-proliferative and anti-migration activity of curcumin loaded in the SEEDS was investigated.
Results
The developed SEDDS (0.05% m/v) showed no cytotoxicity on Caco-2 cells after 3 h of incubation. Glyceryl esters-SEDDS showed a significant higher FDA and curcumin cell uptake than SEDDS without glyceryl ester surfactants (p < 0.05). TGlysurf9-SEDDS showed thereby the most pronounced permeation enhancing properties. TEER remained constant during the permeation study. Curcumin loaded in TGlysurf9-SEDDS exhibited 1.9-fold higher anti-proliferative effect than curcumin loaded in SEDDS without glyceryl ester surfactants. Furthermore, curcumin loaded in glyceryl ester-SEDDS inhibited Caco-2 cells migration to a higher extent than unloaded curcumin and curcumin loaded in SEDDS without the glyceryl ester surfactants.
Conclusions
Glyceryl ester surfactants and in particular polyglyceryl-3-stearate might be a promising excipient for the formulation of SEDDS exhibiting enhanced cellular uptake and permeation enhancing properties.
