Titanium dioxide coating films color

Interference pigments n. Materials used as pigments, which depend on the interference of light for their color. They are generally made from platelets coated with a thin film of higher refractive index. For example, thin films of titanium dioxide coated on mica flakes are one type manufactured and used today. 

Teraoka R, Matsuda Y, Sugimoto I. Quantitative design for photostabilisation of nifedipine by using titanium dioxide and/or tartrazine as colorants in model film coating systems. J Pharm Pharmacol 1989 41 293-297. 

Investigations, related to the photoprotection of nifedipine tablets using films containing titanium dioxide and/or tartrazine, revealed that the photoprotective effect of a film could be evaluated by using its concentration of colorant (C) and thickness (L) value. This value is the product of concentration of the colorant C and the film thickness L. Tablets coated with films having the same CL value had the same photodegradation rates. Degradation rates were found to be proportional to the CL value for every colorant system tested (18). 

Titanium dioxide is used extensively to impart a white color to film-coated tablets, sugar-coated tablets, and gelatin capsules. It is also used in lakes as an opacifier, to extend the color. See Titanium dioxide for further information. 

The addition of more than about 10% titanium dioxide to a coating solution of hypromellose phthalate, which is used to produce a colored film coating, may result in coating with decreased elasticity and resistance to gastric fluid. ... 

Chem. Descrip. Rutile titanium dioxide, stannic oxide/antimony doped Uses Electroconductive pigment, antistat for anti-electrostatic coatings and primers on plastics, rubber, textiles, recording paper substrates, for mfg. of electronic equip, and components for clean room construction Features Inc. physical str. of moldings and paint films requires smaller loading amts. exc. chem. /physical stability against humidity natural whiteness for easy coloring... 

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