Magnesium Silicate

Synonyms: E553a; synthetic magnesium silicate.

Description: Magnesium silicate occurs as an odorless and tasteless, fine, whitecolored powder that is free from grittiness.

Chemical Name: Silicic acid, magnesium salt

Anticaking agent; glidant.

• Magnesium silicate is used in oral pharmaceutical formulations and
  food products as a glidant and an anticaking agent

Magnesium silicate may decrease the oral bioavailability of drugs such as mebeverine hydrochloride, sucralfate, and tetracycline, via chelation or binding, when they are taken together. The dissolution rate of folic acid, erythromycin stearate, paracetamol and chloroquine phosphate may be retarded by adsorption onto magnesium silicate. Antimicrobial preservatives, such as parabens, may be inactivated by the addition of magnesium silicate. Magnesium silicate is readily decomposed by mineral acids.

Magnesium silicate is used in oral pharmaceutical formulations and is generally regarded as an essentially nontoxic and nonirritant material. Orally administered magnesium silicate is neutralized in the stomach to form magnesium chloride and silicon dioxide; some magnesium is absorbed. Caution should be used when greater than 50 mEq of magnesium is given daily to persons with impaired renal function, owing to the risk of hypermagnesemia.

Observe normal precautions appropriate to the circumstances and quantity of material handled. Eye protection is recommended.

Magnesium aluminum silicate; magnesium metasilicate; magnesium orthosilicate; magnesium trisilicate; talc.