Dry vs. Wet Granulation
Colors can be added to tablets by dry blending them into the compression pre-mix or they can be sprayed on during wet granulation. Due to added costs, nutraceutical tablets are not typically coated unless there is a functional benefit; however, because this process omits high heat, most liquid colors can be utilized.
Color addition to non-coated tablets regularly involves specialty ingredients that are designed to evenly disperse in the powder mix before compression, giving a consistent coloring throughout.
Unlike standard, highly-pigmented natural color powders on the market, DDW’s Vibrant Powders have a low pigment strength, with a vibrant surface shade which allows the same color content to achieve a bright, even hue with decreased speckling in tablets and beverage powders.
If there is a variance in ingredient particle size, granulation can be used to achieve better uniformity before tablet compression. During dry granulation, fine powders are compressed into tablets or rolled through a compactor and later milled to form granules. In wet granulation, liquid actives or colors can be sprayed onto a dry powder. This process evenly coats the entire mix which is then dried to form uniform granules. While the former method is more common due to decreased cost, liquid colors can be used for wet granulation when varying particle sizes in the mix prevent even distribution of powdered colors.