Qualitative identification of permitted and non-permitted color additives in cosmetics.

Color additives are dyes, pigments, or other substances that can impart color when added or applied to foods, drugs, cosmetics, medical devices, or the human body. These substances must be pre-approved by the U.S. Food and Drug Administration (FDA) and listed in the Code of Federal Regulations before they may be used in FDA-regulated products. Both domestic and imported cosmetic products sold in interstate commerce fall under FDA jurisdiction, and FDA's district laboratories use a combination of analytical methods for identifying or confirming the presence of potentially violative color additives. We have developed a qualitative method for identifying 29 water- and methanol-soluble color additives in various types of cosmetic products. The color additives are extracted with combinations of methylene chloride, methanol, acetic acid, and water and are identified by LC with photodiode array detection. Estimated LOD values ranged from 0.1 to 1.5 mg/L. A survey of lip products, nail polishes, eye products, blushes, body glitter, face paints, bath products, creams, and toothpastes identified permitted and non-permitted color additives. Our new LC method is intended to supplement the visible spectrophotometry and TLC methods currently used by FDA's district laboratories and will help optimize the use of time, labor, and solvents.

Survey of cosmetics for arsenic, cadmium, chromium, cobalt, lead, mercury, and nickel content.

As part of efforts to assess amounts of inorganic element contamination in cosmetics, the U.S. Food and Drug Administration contracted a private laboratory to determine the total content of seven potentially toxic or allergenic elements in 150 cosmetic products of 12 types (eye shadows, blushes, lipsticks, three types of lotions, mascaras, foundations, body powders, compact powders, shaving creams, and face paints). Samples were analyzed for arsenic, cadmium, chromium, cobalt, lead, and nickel by inductively coupled plasma-mass spectrometry and for mercury by cold vapor atomic fluorescence spectrometry. The methods used to determine the elements were tested for validity by using standard reference materials with matrices similar to the cosmetic types. The cosmetic products were found to contain median values of 0.21 mg/kg arsenic, 3.1 mg/kg chromium, 0.91 mg/kg cobalt, 0.85 mg/kg lead, and 2.7 mg/kg nickel. The median values for cadmium and mercury were below the limits of detection of the methods. The contract requirements, testing procedures, and findings from the survey are described.

Determination of seven certified color additives in food products using liquid chromatography.

This study describes a new method for determining FD&C Blue No. 1, FD&C Blue No. 2, FD&C Green No. 3, FD&C Red No. 3, FD&C Red No. 40, FD&C Yellow No. 5, and FD&C Yellow No. 6 in food products. These seven color additives are water-soluble dyes that are required to be batch certified by the U.S. Food and Drug Administration (FDA) before they may be used in food and other FDA-regulated products. In the new method, the color additives are extracted from a product using one of two procedures developed for various product types, isolated from the noncolored components, and analyzed by liquid chromatography with photodiode array detection. The method was validated by determining linearity, range, precision, recovery from various matrices, limit of detection, limit of quantitation, and relative standard deviation for each color additive. A survey of 44 food products, including beverages, frozen treats, powder mixes, gelatin products, candies, icings, jellies, spices, dressings, sauces, baked goods, and dairy products, found total color additives ranging from 1.9 to 1221 mg/kg. FDA intends to use the new method for conducting a rigorous, comprehensive dietary exposure assessment of certified color additives in products likely to be consumed by children.

Ultra-performance liquid chromatographic determination of manufacturing intermediates and subsidiary colors in D&C Red No. 34 and its lakes.

An ultra-performance liquid chromatography (UPLC) method was developed to determine the manufacturing intermediates and subsidiary colors in the monosulfo monoazo color additive D&C Red No. 34 and its lakes. This method is currently used for batch certification of the color additives by the U.S. Food and Drug Administration to ensure that each lot meets published specifications for coloring drugs and cosmetics. The new UPLC method has replaced an HPLC method for determining the intermediates and a TLC method for determining the subsidiary colors. The intermediates are 2-amino-1-naphthalenesulfonic acid (Tobias acid) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). Subsidiary colors are positional isomers of the major dye component or related compounds containing lower numbers of substituent groups. The analytes are identified by comparison of their UPLC retention times and UV or visible absorption spectra with those of standards. Validation studies showed that peak area calibrations for the analytes were generally linear (R > 0.999), and recoveries were 98-103%. The LODs were 0.002-0.02%, and the RSDs at the specification levels were 0.7-2.2%. Survey analyses of 12 samples of certified D&C Red No. 34 straight colors and lakes from six domestic and foreign manufacturers yielded results for the intermediates by UPLC and HPLC that were consistent within experimental error. The UPLC analyses yielded results for the subsidiary colors that were consistently lower than results previously obtained by TLC, which we attribute to limitations of the TLC method. The new UPLC method provides sharper peaks, better peak separation, and faster analysis times than the formerly used HPLC method and is more accurate, much faster, and much less labor-intensive than the formerly used TLC method.

Reversed-phase LC determination of two manufacturing intermediates, the unsulfonated subsidiary color, and 4-methyl-Sudan I in D&C Red No. 6, D&C Red No. 7, and their lakes.

A reversed-phase liquid chromatographic (LC) method was developed to determine 4 impurities in the monosulfo monoazo color additives D&C Red No. 6, D&C Red No. 7, and their lakes. Manufacturing intermediates determined are 2-amino-5-methylbenzenesulfonic acid (PTMS) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). Subsidiary colors determined are the unsulfonated and uncarboxylated, unsulfonated homologs of the dye (the unsulfonated subsidiary color and 4-methyl-Sudan I). The new method uses lithium oxalate as part of a novel system to dissolve the water-insoluble color additives. The 4 impurities were identified by LC and UV-visible spectrophotometry; the 4-methyl-Sudan I was confirmed by LC/mass spectrometry. LC peak area calibrations were generally linear (R > 0.999), and recoveries ranged from 90 to 105%. The limits of determination used were 0.02% each for PTMS and 3-hydroxy-2-naphthoic acid, 0.1% for the unsulfonated subsidiary color, and 0.002% for 4-methyl-Sudan I. The relative standard deviations at the specification levels ranged from 0.7 to 22.7%. Survey analyses of 26 samples of certified D&C Red Nos. 6 and 7 straight colors and lakes from 11 domestic and foreign manufacturers yielded results that agree with those previously obtained using 3 other methods.

Reversed-phase liquid chromatographic determination of two manufacturing intermediates in D&C Red No. 34 and its lakes.

A reversed-phase LC method was developed to determine two manufacturing intermediates in the monosulfo monoazo color additive D&C Red No. 34 and its lakes. The analytes are 2-amino-1-naphthalenesulfonic acid (Tobias acid) and 3-hydroxy-2-naphthalenecarboxylic acid (3-hydroxy-2-naphthoic acid). This method can be used for batch certification of the color additives by the U.S. Food and Drug Administration to ensure that each lot meets published specifications for coloring drugs and cosmetics. The new method uses lithium oxalate in methanol-water to dissolve the color additives for analysis. The analytes were identified by comparison of their LC retention times and UV absorption spectra with those of standards. Peak area calibrations were generally linear (R > 0.999) and recoveries were 105% for Tobias acid and 103% for 3-hydroxy-2-naphthoic acid. The limits of determination (LOD) were 0.01% for Tobias acid and 0.03% for 3-hydroxy-2-naphthoic acid. The RSDs at the specification levels were 0.9% for Tobias acid and 3.2% for 3-hydroxy-2-naphthoic acid. Survey analyses of 14 samples of certified D&C Red No. 34 straight colors and lakes from six domestic and foreign manufacturers yielded results for Tobias acid that generally agreed with results previously obtained by using a gravity elution column chromatographic method. Nine of the results for 3-hydroxy-2-naphthoic acid were 2 to 5 times higher than the results obtained using the column chromatographic method. We attribute the lower accuracy of the column chromatographic method to incomplete solubility of the samples using the method conditions and difficulty with interpreting the UV spectrophotometric results.