Figure 9: The UV absorbances of 0.25% retinyl palmitate formulations before irradiation (dark blue, dashed line) and after 5 MED (red and green—approx. the amount of UVR in one hour’s worth of mid-summer sun.

The formulation with 4% EHMC (blue) lost about 1% of its UV absorbance, indicating little if any loss of retinyl palmitate. The formulation without EHMC lost 93% of its UV absorbance.