Magnesium trisilicate

Absorption

The hydrated silicon dioxide formed in the stomach and passes into the intestinal track where, silica can be partly absorbed.

Toxicity

Adequate doses of magnesium trisilicate may cause diarrhea due to the action of soluble magnesium salts in the enteric tract. Approx 5% of the magnesium is absorbed.

Chemical properties

White or almost white powder.

Chemical properties

The USP 32 describes magnesium trisilicate as a compound of magnesium oxide and silicon dioxide with varying proportions of water. It contains not less than 20.0% of magnesium oxide and not less than 45.0% of silicon dioxide. The PhEur 6.0 similarly describes magnesium trisilicate as having a variable composition corresponding to the approximate formula Mg₂Si₃O₈·xH₂O. It contains not less than 29.0% of magnesium oxide and not less than the equivalent of 65.0% of silicon dioxide, both calculated with reference to the ignited substance.
Magnesium trisilicate occurs as an odorless and tasteless, fine, white-colored powder that is free from grittiness.

The Uses of Magnesium trisilicate

Industrial odor absorbent, decolorizing agent, antioxidant, medicine (antacid).

Background

Magnesium trisilicate is an inorganic compound that is used as an antacid in the treatment of peptic ulcers.

Indications

For the treatment of peptic ulcers. Relieving indigestion and heartburn.

Definition

USP specifies not less than 20% magnesium oxide and 45% SiO2, similar to the FCC requirements for magnesium silicate. See talc.

Production Methods

Magnesium trisilicate may be prepared from sodium silicate and magnesium sulfate. It also occurs in nature as the minerals meerschaum, parasepiolite, and sepiolite.

brand name

Trimax (Sterling Winthrop).

Pharmaceutical Applications

Magnesium trisilicate is used in oral pharmaceutical formulations and food products as a glidant. It is also used therapeutically as an antacid, and also for the treatment of ciprofloxacin overdose or toxicity.

Pharmaceutical Applications

Magnesium trisilicate (Mg₂Si₃O₈) can be used in antacid preparations especially in the treatment of peptic ulcers. The mode of action includes the increase of the pH of the gastric fluid together with the formation of a colloidal silica precipitate,which forms a protection for theGImucosa. Magnesium trisilicate reduces the absorption of iron products, certain antibiotics (such as Nitrofurantoin) or antimalarial drugs (such as Proguanil).

Pharmacokinetics

Magnesium trisilicate works by increasing the pH of gastric juice via a neutralisation reaction. It also precipitates colloidal silica, which can coat gastrointestinal mucosa conferring further protection.

Safety

Magnesium trisilicate is used in oral pharmaceutical formulations and is generally regarded as an essentially nontoxic and nonirritant material.
When administered orally, magnesium trisilicate is neutralized in the stomach to form magnesium chloride and silicon dioxide; some magnesium may be absorbed. Caution should be used when concentrations greater than 50 mEq of magnesium are given daily to persons with impaired renal function, owing to the risk of hypermagnesemia.
Therapeutically, up to about 2 g of magnesium trisilicate may be taken daily as an antacid. Reported adverse effects include the potential for osmotic diarrhea in the elderly using antacids containing magnesium trisilicate;and the potential for the formation of bladder and renal calculi following the long-term use of magnesium trisilicate as an antacid.

Metabolism

Not Available

storage

Magnesium trisilicate is stable if stored in a well-closed container in a cool, dry place.

Incompatibilities

Magnesium trisilicate, when taken with drugs such as mebeverine hydrochloride,proguanil,norfloxacin,sucralfate, and tetracycline, may cause a reduction in bioavailability via binding or chelation. The dissolution rate of folic acid, erythromycin stearate,paracetamol, and chloroquine phosphate may be retarded by adsorption onto magnesium trisilicate. Antimicrobial preservatives, such as the parabens, may be inactivated by the addition of magnesium trisilicate.
Magnesium trisilicate is also readily decomposed by mineral acids.

Regulatory Status

GRAS listed. Accepted for use as a food additive in Europe. Included in the FDA Inactive Ingredients Database (oral tablets). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.