FD C dyes

The terms FD C, D C, and External D C (Ext. D C), which are part of the name of colorants, reflect the FDA s colorant certification. FD C dyes may be used for foods, dmgs, and cosmetics D C dyes are allowed in dmgs and cosmetics and Ext. D C dyes are permitted only in topical products. Straight colorants include both the organic dyes and corresponding lakes, made by extending the colorant on a substrate such as aluminum hydroxide or barium sulfate. The pure dye content of these lakes varies from 2 to 80% the organic dyes contain over 80% pure dye. Colorants certified for cosmetic use may not contain more than 0.002% of lead, not more than 0.0002% of arsenic, and not more than 0.003% of heavy metals other than lead and arsenic. 

Blue—amiodarone (blue-gray), FD C dye no. 1, and methylene blue... 

Rhodamine dyes were used as test compounds for the detection of the positive-ion mode while FD C dyes were detected in the negative-ion mode. Stationary phases for... 

HT McKone, K Ivie. An introduction to high performance liquid chromatography separation of some FD C dyes. J Chem Educ 57(4) 321-322, 1980. 

The testing procedure involving colonized bacteria Pseudomonas aureus in the protocol was too challenging for the water-based dressing and resulted in unacceptable mortality of rats. In follow-up tests, FD C dyes were observed to penetrate the thickness of the dressing to the tissue, which means that the barrier was permeable to bacteria. Chlorhexidine added to the aqueous and polymer phase of the emulsion produced acceptable results in Kirby-Bauer tests, but not inoculation tests with bacteria on excised rats. 

The barrier dressings formed over agar plates and porcine tissue were successful. No Kirby-Bauer tests have been performed on excised rats to date. The dressing forms a water-impermeable barrier, is impermeable of FD C dyes, and materials with these properties are impermeable to dyes (see Figs. 2.11 and 2.12). 

As an investigative project, the student should verify the literature procedure, select several samples, and determine which FD C dyes are present. 

Solutions of phenylephrine hydrochloride, for example, develop a brown color as a result of photodegradation (2). Many dyes, including FD C dyes, used for coloring liquid pharmaceutical preparations such as syrups and elixirs, fade on exposure to light (9). Curcumin, a natural food colorant, fades on exposure to UV-VIS radiation (10). 

The present list of FD C certified colorants consists of both dyes and lakes. Lakes are pigments. They are insoluble materials that color by dispersion and reflected light. FD C dyes are water-soluble and exhibit their color by transmitted light. 

FD C dyes Today, FD C dyes are synthetic organic molecules produced from highly purified intermediates derived from petrochemicals and other sources. The stigma of the association of FD C dyes with coal tar no longer exists because of these starting materials. They are marketed in a number of physical forms, such as powder, granular, pastes, liquids, and dispersions. Many of these forms are customized for specific uses and are selected by the user for their particular application. 

FD C lakes The only lakes permitted for use in all three categories—foods, drugs, and cosmetics—are the aluminum lakes. These are manufactured through the adsorption of an aluminum salt of an FD C dye on a base of alumina hydrate. 

Analogous stability problems exist between D C, external D C, and FD C dyes, although there are a few D C colors that are considerably more stable than the FD C colorants. 

Contact allergy to the paraphenylene group of hair dyes is well estabhshed (2). To test for cross-reactivity between these oxidative dyes and the new generation of hair dyes, 40 hairdressers allergic to paraphenylenediamine were selected none reacted to any of the four acid dyes, two FD C dyes, or four D C dyes, suggesting that these newer hair dyes are safe alternatives to the para-phenylene-based hair dyes (3). 

Hjort N, Trolle-Lassen C (1962) Skin reactions to preservatives with special regard to para-ben esters and sorbic acid. Arch Pharm Chem 69 9-16 Hosen H (1972) The relationship of FD C dyes and respiration allergy. J Asthma Res 10 131-134... 

Combination of DESI MS with TLC separation was proposed for the first time by Van Berkel et al. [1]. In their study, apart from showing the possibility of such connection, the authors demonstrated practical application of this method during analyses of the FD C dyes (food dyes) and a mixture of aspirin, acetaminophen, and caffeine from a tablet of Extra Strength Excedrin. In the following year, this systan was further upgraded and improved by automating the process of analysis [2]. It was then used to separate the Goldenseal (Hydrastis canadensis) and related alkaloids from... 

CW Brown, PF Lynch. Identification of FD C dyes by resonance Raman-spectroscopy. J Food Sci 41 1231-1232, 1976. 

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