Ceramide Profiling of Porcine Skin and Systematic Investigation of the Impact of Sorbitan Esters (SEs) on the Barrier Function of the Skin.

Summary

Using LC-MS ceramide profiling, TEWL, and confocal Raman spectroscopy, sorbitan esters were shown to be skin-friendly emulsifiers: SE60 (and cholesterol) minimized ceramide depletion, and SE40/60/80/120 did not increase TEWL. Structural parameters by Raman remained stable, supporting barrier-compatible formulation choices.

Key Findings

• SEs are complex mixtures of mono-, di-, and triesters with varied fatty acid distributions.
• SE60 and cholesterol caused the least ceramide depletion by LC‑MS profiling; SE40/60/80/120 did not increase TEWL.
• Confocal Raman spectroscopy showed largely unchanged lipid chain order, conformation, and stratum corneum thickness; lipid content decreased except with SE120.

Clinical Implications

Supports preferring SE-based emulsifiers (notably SE60) when barrier preservation is critical (e.g., atopic skin, retinoid regimens), and cautions against SLS; informs excipient selection in dermatologic and cosmetic products.

Limitations

• Porcine skin/ex vivo model may not fully capture human clinical responses or chronic exposure.
• Formulation matrices and long-term repeated-use scenarios were not tested.

Future Directions

Human in vivo TEWL/biophysical studies, longitudinal use testing in sensitive skin cohorts, and head-to-head comparisons with alternative emulsifiers and surfactants.