Packaging and storage—
Preserve in well-closed containers.
Labeling—
Tablets prepared with the use of Dried Aluminum Hydroxide Gel may be labeled to state the aluminum hydroxide content in terms of the equivalent amount of dried aluminum hydroxide gel, on the basis that each mg of dried gel is equivalent to 0.765 mg of Al(OH)3.
Identification—
A:
To a 0.7-g portion of finely powdered Tablets add 10 mL of 3 N hydrochloric acid and 5 drops of
methyl red TS, heat to boiling, and add 6 N ammonium hydroxide until the color of the solution changes to deep yellow. Continue boiling for 2 minutes, and filter: the filtrate responds to the tests for
Magnesium 
191
.
B:
Wash the precipitate obtained in
Identification test
A with a hot solution of ammonium chloride (1 in 50), and dissolve the precipitate in hydrochloric acid: the solution responds to the tests for
Aluminum 191.
Disintegration 701:
10 minutes, simulated gastric fluid TS being substituted for water in the test.
Acid-neutralizing capacity 301—
The acid consumed by the minimum single dose recommended in the labeling is not less than 5 mEq, and not less than the number of mEq calculated by the formula:
0.55(0.0385A) + 0.8(0.0343 M),
in which 0.0385 and 0.0343 are the theoretical acid-neutralizing capacities, in mEq, of Al(OH)
3 and Mg(OH)
2, respectively, and
A and
M are the quantities, in mg, of Al(OH)
3 and Mg(OH)
2 in the specimen tested, based on the labeled quantities.
Assay for aluminum hydroxide—
Edetate disodium titrant—
Prepare and standardize as directed in the
Assay under
Ammonium Alum.
Assay preparation—
Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 1200 mg of aluminum hydroxide, to a 150-mL beaker, add 20 mL of water, stir, and slowly add 30 mL of 3 N hydrochloric acid. Proceed as directed for
Assay preparation in the
Assay for aluminum hydroxide under
Alumina and Magnesia Oral Suspension, beginning with “Heat gently, if necessary.”
Assay for magnesium hydroxide—
Auxiliary Information—
Staff Liaison :
Elena Gonikberg, Ph.D., Scientist
Expert Committee : (MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
USP29–NF24 Page 86
Pharmacopeial Forum : Volume No. 27(3) Page 2515
Phone Number : 1-301-816-8251
