Coloring Agents in Pharmaceutical Industry

COLOURING AGENTS

Coloring agents or color additive is any dye, pigment, or substance that imparts color when it is added to food or drink or drug. They come in many forms consisting of liquids, powders, gels, and pastes.

Properties

1. A colorant becomes an integral part of pharmaceutical preparation.
2. The amount of colorants generally added to liquid preparation normally ranges from 0.0005 to 0.001%.
3. Normally the colorants are added to pharmaceutical preparation in dilute solution for uniformity of color in the finished product.

CLASSIFICATION

(I) Natural coloring agent

These are obtained from mineral, plant, and animal sources.they are used as colors for foods, drugs, and cosmetics.these are of three types-

(a) Mineral colors

These are frequently termed as pigments and used to color lotions, cosmetics, and other preparation for external use. There are minerals such as manganese, chromium oxide, aluminum powder, iron oxide, coal tar (the dark and sticky liquid produced from coal heated in the air-free oven).

(b) Plant colors-

Coloring principles from plants are normally obtained by extraction. Examples – • Beta-carotene With Natural Colorant • Turmeric Oil • Natural Mentha oil 50% min. • Tomato juice concentrate • Bilberry Anthocyanidin

(c) Animal source

Cochineal obtained from the insect coccus cacti contains the bright red coloring principle, carminic acid. tyrian purple was prepared by air oxidation of glandular secretion of a snail, murex brandaris. Cochineal, a red dye derived from the cochineal insect, Dactylopius coccus.

(II)Synthetic Colour

Synthetic color or FD&C colors are mostly derived from coal tar. Many have been banned from food by the FDA for various reasons: carcinogenicity, allergy-inducing, general toxicity, etc. A number caused illnesses in children. They have been shown in clinical studies to cause various types of cancer.

(III) Lakes

A lake pigment is a pigment manufactured by precipitating a dye with an inert binder, or “mordant”, usually a metallic salt. This sense of a lake is unconnected with the lake meaning body of water; it derives from the word lac.
Examples-
(1) Indigo lake
(2) Rose madder lake
(3) Carmine lake

Widely used coloring agents in a pharmaceutical company-
• FD&C Blue No. 1 (brilliant blue FCF)
• FD&C Blue No. 2 (indigotine)
• FD&C Green No. 3 (fast green FCF)
• FD&C Red No. 40 (allura red AC)
• FD&C Red No. 3 (erythrosine)
• FD&C Yellow No. 5 (tartrazine)
• FD&C Yellow No. 6 (sunset yellow)
• Turmeric- Turmeric is readily available for cuts, burns, and bruises. It helps in detoxication of the liver. It helps in balancing of Cholesterol level.
• Silica gel for pharmaceutical use
• Pharmaceutical agar-agar powder- Agar-agar has wide application in food, pharmacy, daily chemistry, and biochemistry in meat canning; in production of medicinal encapsulations and ointments; as dental impression mold base.