a Retinol (99%) and retinyl palmitate (18,000,000 USP Units/G) were obtained from Sigma-Aldrich.
b Solastay S1 (INCI: Ethylhexyl Methoxycrylene) is a product of The HallStar Company.
c The Varian Cary 50 CONC UV/Vis spectrophotometer was used for this analysis.
d Whatman Catalog #4420221 TLC plates were used for this study.
e The Spectroline Model ENF-240C lamp was used for this study.
f The model D70 camera used for this study is manufactured by Nikon.
g The Hewlett Packard Series 1100 HPLC System was used for this analysis.
h ChemStation for LC 3D is produced by Agilent Technologies.
j The Apollo C18 column (4.6 x 150 mm, with a 5-μm particle size) was used for this assessment.
k The Model 16S Solar Simulator with a PMA 2105 UV-B DCS Detector controlled by a PMA 2100 microprocessor-based controller used for this study is a device from Solar Light Co.
m The Labsphere UV-2000S UV Transmittance Analyzer was used for this assessment.
n The Helioplate HD6 PMMA plates used for this study are manufactured by HelioScreen Labs.