Figure 5. Portions of the HPLC chromatograms from the retinol studies showing the relative heights of the peaks for BHT (blue), used as the internal standard, and retinol (orange)

a) The formulation without EHMC lost 79% of its retinol, while b) the formulation with 4% EHMC lost less than 5% of its retinol. The E and Z isomers of EHMC are in yellow. Other peaks represent the excipients used to make the formulations.