Packaging and storage— Preserve in well-closed containers.

Identification— Crush several Tablets,and dissolve 1g of the powder in 20mLof 3Nhydrochloric acid:the solution responds to the tests for Magnesium á191ñ.

Disintegration á701ñ: 10minutes,simulated gastric fluid TSbeing substituted for water in the test.

Uniformity of dosage units á905ñ: meet the requirements.

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: in which 0.0343is the theoretical acid-neutralizing capacity,in mEq,of Mg(OH)2;andMis the quantity,in mg,of Mg(OH)2in the specimen tested,based on the labeled quantity.

Assay— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 250mg of magnesium hydroxide,to a 100-mLvolumetric flask,and proceed as directed in the Assayunder Milk of Magnesiabeginning with “Dissolve in 10mLof 3Nhydrochloric acid.”

Expert Committee:(PA4)Pharmaceutical Analysis 4

USP28–NF23Page 1166

Phone Number:1-301-816-8251