Aluminum lakes

Carmine [1390-65-4] is the aluminum or calcium-aluminum lake on an aluminum hydroxide substrate of the coloring principle (again, chiefly carminic acid) obtained by the aqueous extraction of cochineal. Carmine is normally 50% or more carminic acid. 

Carmine [1390-65-4] is the trade name for the aluminum lake of the red anthraquinone dye carminic acid obtained from the cochineal bug. The dye is obtained from the powdery form of cochineal by extraction with hot water, the extracts treated with aluminum salts, and the dye precipitated from the solution by the addition of ethanol. This water-soluble bright red dye is used for coloring shrimp, pork sausages, pharmaceuticals, and cosmetics. It is the only animal-derived dye approved as a colorant for foods and other products. 

In a subsequent work, Raff used the CIE system to quantify the colors that could be obtained when using FD C aluminum lakes as colorants in tablet formulations [43]. He reported on the concentration dependence of the tristimulus values obtained when calcium sulfate dihydrate was compressed with various amounts of FD C Blue No. 2 aluminum lake, and one example of the reported data is found in Table 1. 

Table 1 Tristimulus Values Obtained on a Series of Tablets Colored with FD C Blue No. 2 Aluminum Lake...

The effect of particle size, and hence dispersion, on the coloring properties of aluminum lake dyes has been studied through quantitative measurement of color in compressed formulations [47], It was found that reduction in the particle size for the input lake material resulted in an increase in color strength, and that particles of submicron size contributed greatly to the observed effects. Analysis of the formulations using the parameters of the 1931 CIE system could only lead to a qualitative estimation of the effects, but use of the 1976 CIEL m v system provided a superior evaluation of the trends. With the latter system, the effects of dispersion on hue, chroma, lightness, and total color differences were quantitatively related to human visual perception. 

FD C Yellow No. 5 Aluminum Lake, in nail-care products, 7 853 FDA Bureau of Drug Abuse Control,... 

Aluminum lakes of P.0.17 l are available in the USA. Properties which are pertinent to the coloristics and application of the pigment parallel those of the barium lakes. P.O,17 l, an equally high strength pigment, also affords brilliant shades and is used in packaging prints, especially for paraffin-based wrapping paper for bread. 

The pigment is then laked according to the procedure described for [3-naphthol pigments (Sec. 2.7.1.1). Aluminum lakes are an exception. A soluble aluminum salt is first converted to aluminum oxide hydrate, which is washed to remove salt. The moist product is then combined with the dye solution, while a more soluble aluminum salt is added simultaneously. The insoluble pigment is finally washed salt-free and dried. 

Likewise, P.B.63 is an aluminum lake. It is derived from the indigo structure, which is sulfonated to afford indigo-5,5 -disulfonic acid. For indigo syntheses, please see [1]. 

The aluminum lake is registered throughout the EC as E 132, in the USA as FD C Blue 2 as a colorant for foodstuffs and pharmaceuticals, provided certain purity conditions are met. Its shade is a bluish red. The pigment is somewhat sensitive to chemicals and to overcoating as well as to light. It is a tinctorially weak product. 

The structure of kermisic acid is l,3,4,5-tetrahydroxy-7-carboxy-8-mcrhylanthraquinone. Carminic acid (Cl Natural Red 4 Cl 75470). is a red dye occurring as a glycoside in the body of the cochineal insect Dactylopius coccus of the order Homoptera. family Coecidae, Until the advent of synthetic dyes, the principal use for carminic acid was for dyeing tin-mordanted wool or silk. Its aluminum lake, carmine, finds use in Lhe coloring of foods. The structural formula of carminic acid is (2). 

Carmine occurs as bright red, friable pieces or as a dark red powder. It is the aluminum or the calcium-aluminum lake, on an aluminum hydroxide substrate, of the coloring principles obtained by an aqueous extraction of cochineal. Cochineal consists of the dried female insects Dactylopius coccus costa (Coccus cacti L.), enclosing young larvae the coloring principles thus derived consist mainly of carminic acid (C22H20O13). It is soluble in alkali solutions, slightly soluble in hot water, and practically insoluble in cold water and in dilute acids. 

Colorants can be divided into water-soluble dyes and water-insoluble pigments. Some of the insoluble colors or pigments can also provide opacity to tablet coatings or gelatin shells, which can promote stability of light-sensitive active materials. Pigments such as the iron oxides, titanium dioxide, and some of the aluminum lakes are especially useful for this purpose. 

PONCRAU 4R PONCEAU 4R ALUMINUM LAKE PONTACYL SCARLET RR PURPLE RED ROUGE de COCHENILLE A SAN-EI BRILLIANT SCARLET 3R STRAMEERRY RED A GEIGY SYMULON ACID BRILLIANT SCARLET 3R TARAOKA BRILLIANT SCARLET 3R VICTORIA SCARLET 3R... 

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. 

Note Aluminum lakes prepared from colors mentioned in this list are also authorized. 

Based on colors approved by the MHW s Aluminum lakes of these colors are also authorized. (From Ref.. )... 

If the lakes used are aluminum lakes, the alumina substrate contains water of hydration, and the lake itself may have total moisture content of between 12 and 25%. High processing temperatures can release some of the hydrated water however, in most pharmaceutical applications this is not a problem. 

Table 10 FD C aluminum lakes typical physical data...

A hydroxypropyl methylcellulose film of pigment was exposed in a fadeometer for 3, 6, and 12 h. The rate at which the colorant degraded was noted from tint strength calculations and placed on a scale of 0-10, with the higher numbers indicating an increased tendency to fade. AL-aluminum lake. 

Most aluminum lakes are within a pH range of 4.0-8.0. Outside this range, the dye and substrate may be separated and the lake dissolved. Other lakes may exhibit some stability outside of this range. The color shade of a lake may also vary with pH. 

Nyamweya, N. Mehta, K.A. Hoag, S.W. Characterization of the interactions between polymethacrylate-based aqueous polymeric dispersions and aluminum lakes. J. Pharm. Sci. 2001, 90, 1-11. 

Table V Typical characteristic properties of aluminum lakes. ...

---