Figure 1. The molecular structure and the two isomers of EHMC; both isomers are always present in some proportion and account for the two peaks in the HPLC chromatograms.

Considering these instability issues, the authors sought to determine whether ethylhexyl methoxycrylene (EHMC), an effective photostabilizer for certain organic UV filters (see Figure 1), could perform the same photostabilizing function for topically applied retinoids.