Magnesia Tablets contain NLT 93.0% and NMT 107.0% of the labeled amount of magnesium hydroxide [Mg(OH)2].
• A. Identification TestsGeneral, Magnesium 191
Sample solution: Crush several Tablets, and dissolve 1 g of the powder in 20 mL of 3 N hydrochloric acid.
Acceptance criteria: Meet the requirements
Sample solution: Finely powder NLT 20 Tablets. Transfer a portion of the powder, equivalent to 250 mg of magnesium hydroxide, to a 100-mL volumetric flask. Dissolve in 10 mL of 3 N hydrochloric acid, and dilute with water to volume. Filter, if necessary, and transfer 25.0 mL of the filtrate to a beaker containing 75 mL of water.
Analysis: Adjust the reaction of the solution with 1 N sodium hydroxide to a pH of 7 (using pH indicator paper; see Reagents, Indicators, and SolutionsIndicator and Test Papers), and add 5 mL of ammoniaammonium chloride buffer TS and 0.15 mL of eriochrome black TS. Titrate with 0.05 M edetate disodium VS to a blue endpoint. Each mL of 0.05 M edetate disodium is equivalent to 2.916 mg of Mg(OH)2.
Acceptance criteria: 93.0%107.0%
• Disintegration 701
Time: NMT 10 min, simulated gastric fluid TS being substituted for water in the test
• Uniformity of Dosage Units 905: Meet the requirements
• Acid-Neutralizing Capacity 301
Analysis: NLT 5 mEq of acid is consumed by the minimum single dose recommended in the labeling, and NLT the number of mEq calculated by the formula:
Result = (FM × M) × 0.8
• Packaging and Storage: Preserve in well-closed containers.
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3741