Magnesium Aluminosilicate
(mag nee' zee um a loo'' mi noe sil' i kate).
» Magnesium Aluminosilicate is a synthesized material that contains not less than 20.5 percent and not more than 27.7 percent of magnesium oxide (MgO), not less than 27.0 percent and not more than 34.3 percent of aluminum oxide (Al2O3), and not less than 14.4 percent and not more than 21.7 percent of silicon dioxide (SiO2), calculated on the dried basis.
Packaging and storage— Preserve in tight containers, and prevent exposure to excessive heat.
Acid-consuming capacity— Transfer about 0.2 g of Magnesium Aluminosilicate, accurately weighed, to a glass-stoppered flask, and add 100.0 mL of 0.1 N hydrochloric acid VS. Stopper the flask tightly, shake at 37 ± 2 for 1 hour, and filter. Transfer 50.0 mL of the filtrate to a beaker, and, while stirring, titrate the excess hydrochloric acid with 0.1 N sodium hydroxide VS to attain a pH of 3.5. Perform a blank determination, and make any necessary correction: not less than 250 mL of 0.1 N hydrochloric acid is consumed per g of Magnesium Aluminosilicate, calculated on the dried basis.
pH 791 Transfer 2 g of Magnesium Aluminosilicate to a suitable container, and add 50 mL of water. While stirring, immerse the pH electrodes in the suspension, and after 2 minutes record the pH: between 8.5 and 10.5.
Other requirements— It meets the requirements for Identification, Loss on drying, Soluble salts, Alkalinity, Chloride, Sulfate, Arsenic, Iron, and Heavy metals under Magnesium Aluminometasilicate.
Assay for aluminum oxide, magnesium oxide, and silicon dioxide— Proceed as directed in the Assay for aluminum oxide, the Assay for magnesium oxide, and the Assay for silicon dioxide under Magnesium Aluminometasilicate.
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Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, M.S.
Scientific Liaison
(EXC2010) Monographs - Excipients
USP35–NF30 Page 1845
Pharmacopeial Forum: Volume No. 28(4) Page 1217