Chemical Properties
White or almost white powder.
Brand name
Trimax (Sterling
Winthrop).
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.
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).
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.
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.
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.
