Magnesia Tablets
» Magnesia Tablets contain not less than 93.0 percent and not more than 107.0 percent of the labeled amount of magnesium hydroxide [Mg(OH)2].
Packaging and storage— Preserve in well-closed containers.
Identification— Crush several Tablets, and dissolve 1 g of the powder in 20 mL of 3 N hydrochloric acid: the solution responds to the tests for Magnesium 191.
Disintegration 701: 10 minutes, simulated gastric fluid TS being substituted for water in the test.
Uniformity of dosage units 905: meet the requirements.
Acid-neutralizing capacity 301 Not less than 5 mEq of acid is consumed by the minimum single dose recommended in the labeling, and not less than the number of mEq calculated by the formula:
in which 0.0343 is the theoretical acid-neutralizing capacity, in mEq, of Mg(OH)2; and M is the quantity, in mg, of Mg(OH)2 in the specimen tested, based on the labeled quantity.
Assay— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 250 mg of magnesium hydroxide, to a 100-mL volumetric flask, and proceed as directed in the Assay under Milk of Magnesia beginning with “Dissolve in 10 mL of 3 N hydrochloric acid.”
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Elena Gonikberg, Ph.D.
Senior Scientist
(MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
701 Margareth R.C. Marques, Ph.D.
Senior Scientist
(BPC05) Biopharmaceutics05
USP32–NF27 Page 2828