The capsule colorants must be edible colorants. Since the capsules are for oral use, the capsule colorants must meet strict safety requirements. In most countries, the dyes and pigments approved for use in capsules are also permitted as food colorants.

Synthetic dyes are the most commonly used dyes

Hard capsules are essentially films that have been shaped into a capsule form. The colorants are added to the film mixture when it is in a liquid state, which means the color is an integral part of the capsule itself rather than just being added as a coating. Therefore, it is not surprising that synthetic dyes are mainly used in a water-soluble form. From a chemical perspective, most synthetic dyes come from one of the following chemical categories: azo dyes, indigoid dyes, quinophthalone dyes, triarylmethane dyes or xanthene dyes.

Synthetic dyes are usually made from iron oxide, especially black iron oxide, red iron oxide, and yellow iron oxide. One of the reasons they are so popular is that they can be used to make gelatin or vegetarian capsules of almost any color, and the color is completely consistent from batch to batch.

Hongkang Capsules offer a variety of standard color options and also provide color customization services, including Pantone color card matching. Brands can choose from multiple color combinations to make their capsules stand out.

Natural dyes are increasingly favored

Thanks to the "pure label" and "sustainable development", the popularity of natural dyes and other natural colorants is increasing, especially in the field of nutritional supplements. Natural dyes make the products more "natural", so most manufacturers using natural dyes in their vegetarian capsules only use these colorants because vegetarian capsules can also meet more "pure label" requirements.

As the name suggests, natural pigments are derived from natural substances, mainly plants. Common natural dyes and pigments sources include Angora red, carmine, chlorophyll, saffron, spirulina, and plant carbon (used to make capsules with a unique black color). In addition to being non-toxic, non-carcinogenic, and environmentally friendly, many natural pigments also have high nutritional value. Because the process of extracting pigments from their sources is not selective, natural pigments will contain some nutrients derived from plants, flowers, or other natural items.

When switching from capsules made with synthetic dyes to those made with natural dyes, there are two things to note. First, since these dyes come from natural sources, the colors of different batches may vary. Second, some natural colorants will fade when exposed to ultraviolet or infrared light for a long time, and this problem needs to be solved through product packaging.