The influence of fat content on the photo-degradation rate of added retinol
in cream was investigated. The shelf-life (t1/2) values were higher in cre
am with increased fat content (60%) compared to the cream with lower fat co
ntent (25%), indicating the protective effect of fat on photo-degradation o
f fortified retinyl palmitate. Shelf-life values were correlated significan
tly (r=0.99) with fat percentage of cream.