Alumina,Magnesia,and Calcium Carbonate Tablets
»Alumina,Magnesia,and Calcium Carbonate Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amounts of aluminum hydroxide [Al(OH)3],magnesium hydroxide [Mg(OH)2],and calcium carbonate (CaCO3).
Packaging and storage— Preserve in well-closed containers.
Labeling— Label the Tablets to indicate that they are to be chewed before being swallowed.Tablets prepared with the use of Dried Aluminum Hydroxide 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 0.765mg of Al(OH)3.
Identification— To a 3-g portion of finely powdered Tablets add 25mLof water and 25mLof 2Nsulfuric acid,stir,and heat on a steam bath for 10minutes.Cool,add 50mLof alcohol,and stir:the mixture so obtained responds to Identificationtests A,B,and Cunder Alumina,Magnesia,and Calcium Carbonate Oral Suspension,beginning under Identificationtest Awith “place in an ice bath for 30minutes.”
Uniformity of dosage units á905ñ: meet the requirements for Weight Variationwith respect to alumina,to magnesia,and to calcium carbonate.
Acid-neutralizing capacity á301ñ— Not less than 5mEq 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:
0.55(0.0385A)+0.8(0.0343M)+0.9(0.02C),
in which 0.0385,0.0343,and 0.02are the theoretical acid-neutralizing capacities,in mEq,of Al(OH)3,Mg(OH)2,and CaCO3,respectively,and A,M,and Care the respective quantities,in mg,of Al(OH)3,Mg(OH)2,and CaCO3in the specimen tested,based on the labeled quantities.
Assay for aluminum hydroxide—
Edetate disodium titrant— Prepare as directed in the Assay for aluminum hydroxide under Alumina,Magnesia,and Calcium Carbonate Oral Suspension.
Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 600mg of aluminum hydroxide,to a beaker,add 20mLof water,and slowly add 40mLof 3Nhydrochloric acid,with mixing.Heat the mixture to boiling,cool,and filter into a 200-mLvolumetric flask.Wash the beaker with water,adding the washings to the filter.Add water to volume,and mix.
Procedure— Proceed as directed for Procedurein the Assay for aluminum hydroxide under Alumina,Magnesia,and Calcium Carbonate Oral Suspension.Each mLof 0.05MEdetate disodium titrantis equivalent to 3.900mg of Al(OH)3.
Assay for magnesium hydroxide—
Edetate disodium titrant and Assay preparation—Prepare as directed in the Assay for aluminum hydroxide.
Procedure— Proceed as directed for Procedurein the Assay for magnesium hydroxideunder Alumina,Magnesia,and Calcium Carbonate Oral Suspension.Each mLof 0.05Medetate disodium is equivalent to 2.916mg of Mg(OH)2.
Assay for calcium carbonate—
Edetate disodium titrant and Assay preparation—Prepare as directed in the Assay for aluminum hydroxide.
Procedure— Proceed as directed for Procedurein the Assay for calcium carbonateunder Alumina,Magnesia,and Calcium Carbonate Oral Suspension.Each mLof 0.05Medetate disodium is equivalent to 5.004mg of CaCO3.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 79
Pharmacopeial Forum:Volume No.29(6)Page 1836
Phone Number:1-301-816-8251