Hazard
Toxic by inhalation, use in foods restricted
to 2%.
Description
Magnesium silicate is very important in the earth
sciences because it is the material that makes up most
of the volume of the Earth. Magnesium silicate can be
prepared by calcining the oxide with silica, SiO2, at an
elevated temperature.
Chemical Properties
A synthetic, usually amorphous form of magnesium silicate in
which the molar ratio of silicon dioxide to magnesium oxide is
approximately 2.2 to 3.3. It occurs as a very fine, white, odorless,
tasteless powder, free from grittiness. It is insoluble in water and
in alcohol, but is readily decomposed by mineral acids. The pH
of a 1 in 10 slurry is between 7.0 and 10.8.
Chemical Properties
Magnesium silicate occurs as an odorless and tasteless, fine, whitecolored
powder that is free from grittiness.
Chemical Properties
white to off-white fine powder
Production Methods
Magnesium silicate may be prepared from sodium silicate and
magnesium sulfate. The silicate also occurs in nature as the minerals
meerschaum, parasepiolite, and sepiolite.
General Description
Florisil, adsorbent for the separation of lipids, is a commercially-prepared magnesia silica gel. It has a coarse mesh size which helps in rapid flow rate. Florisil is effective in promoting [1,3]-sigmatropic shift of myceophenolic acid related allyl phenyl ethers. Florisil cartridges are used in atmospheric sampling to assess possible interference from air contaminants.
Pharmaceutical Applications
Magnesium silicate is used in oral pharmaceutical formulations and
food products as a glidant and an anticaking agent.
Safety
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.
Reported adverse effects include the formation of bladder and
renal calculi following the regular use, for many years, of
magnesium silicate as an antacid.
