Influence of sunscreening agents on color stability of tablets coated with certified dyes III: FD&C Yellow No. 6.

The influence of a protective coating of six sunscreening agents (glyceryl p-aminobenzoate, benzocaine, cinoxate, homosalate, n-octyl salicylate, and amyl salicylate) upon the photostability of FD&C Yellow No. 6 used to color coat tablets was studied. The alcohol film, modified sugar-, and film-coating methods were used to apply the sunscreening agents. Tablets were exposed to 1000 foot-candles of light for various times, after which reflectance measurements and visual observations were recorded. FD&C Yellow No. 6 did not follow the Kubelka-Munk equation. The order of relative stability was FD&C Yellow No. 6 greater than erythrosine sodium (FD&C Red No. 3) greater than FD&C Blue No. 1. The greatest protection against fading was afforded by benzocaine.