Which opacifier is the most commonly used in pharmaceuticals?

Titanium dioxide is the most commonly used opacifier in the pharmaceutical industry due to its excellent properties that make it ideal for various applications. It is renowned for its high refractive index, which makes it very effective at scattering light and providing opacity to formulations. This characteristic helps in masking the color of underlying substances, which is particularly valuable in the formulation of tablets, capsules, and various types of coatings.

In addition to its opacity, titanium dioxide is widely recognized for its stability under a range of pH levels and its low toxicity, making it safe for use in pharmaceutical products, including those intended for human consumption. The ability to create a visually appealing product while ensuring compliance with regulatory standards is a major factor for its widespread use in the industry.

Other mentioned opacifiers do have their applications but do not match the versatility and effectiveness of titanium dioxide in providing opacity. Calcium carbonate, for example, is primarily used as a filler rather than an opacifier. Magnesium carbonate and silicon dioxide serve different purposes, such as acting as anti-caking agents or stabilizers, which makes them less suitable for use as primary opacifiers in pharmaceuticals.