Name: Magnesium Trisilicate
CAS No: Magnesium trisilicate [14987-04-3]
BP: Magnesium Trisilicate PhEur: Magnesium Trisilicate USP: Magnesium Trisilicate
E553a; magnesii trisilicas; magnesium mesotrisilicate; silicic acid, magnesium salt (1 : 2), hydrate.
Magnesium trisilicate [14987-04-3]
Mg2Si3O8xH2O 260.86 (anhydrous)
See Section 4.
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.(1
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 Mg2Si3O8xH2O. 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.
See Table I.
Moisture content Magnesium trisilicate is slightly hygroscopic. At relative humidities of 15–65%, the equilibrium moisture content at 258C is 17–23% w/w; at relative humidities of 75–95%, the equilibrium moisture content is 24–30% w/w. NIR spectra see Figure 1. Solubility Practically insoluble in diethyl ether, ethanol (95%) and water.
Magnesium trisilicate is stable if stored in a well-closed container in a cool, dry place
Magnesium trisilicate, when taken with drugs such as mebeverine hydrochloride,(2) proguanil,(3) norfloxacin,(4) sucralfate, and tetracycline, may cause a reduction in bioavailability via binding or chelation. The dissolution rate of folic acid,(5) erythromycin stearate,(6) paracetamol, and chloroquine phosphate(7) may be retarded by adsorption onto magnesium trisilicate. Antimicrobial preservatives, such as the parabens, may be inactivated by the addition of magnesium trisilicate.(8) Magnesium trisilicate is also readily decomposed by mineral acids.
Magnesium trisilicate may be prepared from sodium silicate and magnesium sulfate. It also occurs in nature as the minerals meerschaum, parasepiolite, and sepiolite.
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;(9) and the potential for the formation of bladder and renal calculi following the long-term use of magnesium trisilicate as an antacid.(10,11)
Observe normal precautions appropriate to the circumstances and quantity of material handled. Eye protection is recommended.
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.
Calcium silicate; magnesium aluminum silicate; magnesium silicate; magnesium trisilicate anhydrous; talc. Magnesium trisilicate anhydrous Empirical formula Mg2Si3O8 Molecular weight 260.86 CAS number [14987-04-3]
Magnesium trisilicate is regarded as a type of magnesium silicate. The European food additive code E553a has been applied to both. The EINECS number for magnesium trisilicate is 239-076-7. The PubChem Compound ID (CID) for magnesium trisilicate is 5311266