Stability of Certified Dyes in Tablets I

Influence of Sunscreening Agents on Color Stability of Tablets Coated with Certified Dyes I: FD&C Red no. 3

“…3 fits a first-order rate equation in the presence and absence of sunscreening agents. The first-order rate constants were calculated (Table I), and the rate constant for this dye is different than those reported previously (3,8). The difference is due to the differences in the overall composition of the coating plus the background material.…”

“…To where Bt = (1 -R)*/2R in which R is the reflectance at the absorbance maximum at time t, Z is the intensity in foot-candles, and k is an apparent first-order rate constant; Ot' is /It at t = 0. The theoretical concepts of the Kubelka-Munk equation and its wide use were described elsewhere (8,9). Figure 2 shows typical plots of Ot Versus product of time and intensity.…”

“…These studies utilized various equations such as the Kubelka-Munk equation (8,9) based on kinetic principles or the AdamsNickerson or McAdam equations (10) based on color differences and chromaticity coordinates. Recently, a fadeometer was employed for the rapid determination of color stability (11).…”

Measurement of Surface Color and Color Difference of Tablet Colorants by Tristimulus Colorimetry

“…Some work also has been reported on color determination and color control in the food industry (3, 4). More recently, colorimetry has been employed in the determination of color stability of pharmaceutical tablet formulations (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) and in the production of color matches for solid dosage forms (19)(20)(21). This work describes the measurement of surface color by tristimulus colorimetry and the determination of color specifications for the routine control of tablet colorants.…”

“…The source consists of a gas-filled tungsten lamp used in conjunction with two color filters (Ref 19,. p. 309) 10. Gardner XL-10, Gardner Laboratory, Inc., Bethesda, Md.…”