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Aluminum Silicate

Medically reviewed by Last updated on Aug 9, 2023.

Excipient (pharmacologically inactive substance)

What is it?

Aluminum silicate (Al2SiO5) is also known as kaolin, or hydrated aluminum silicate when in powder form. Aluminum silicate is a mixture of alumina, silica, and oxygen. Kaolin is often used as a demulcent and adsorbent in pharmaceutical industry. It is used in color lakes (insoluble dyes). As a raw material, it is commonly found in paper, plastics, cosmetics, and pharmaceuticals, and it is also used in pharmaceutical preparations as a filtering agent to clarify liquids. As a medicinal agent, kaolin, is used to treat diarrhea. In dentistry, used to add toughness and opacity to porcelain teeth. Other common names for hydrated aluminum silicate include heavy or light kaolin, china clay, bolus alba, porcelain clay, white bole, and argilla.

List of medications using Aluminum Silicate


  1. Natural Products Consumer Database. Accessed January 10, 2014.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.