Long-chain, complex fatty alcohol that functions as a water-binding agent and also has preservative qualities. Its name is derived from the term sphingoid, coined in 1884 by chemist J. L. W. Thudichum because the way the molecules of this substance lined up reminded him of the riddle of the Sphinx. It seems this ingredient can also be a skin-restoring ingredient, albeit one that is best for compromised skin.
References for this information:
Journal of Investigative Dermatology, October 2003, issue 5, pages 1135–1137
Molecular Medicine, January-March 2006, pages 17-24