Calcium and Magnesium Carbonates Tablets
Calcium and Magnesium Carbonates Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of calcium carbonate (CaCO3) and NLT 85.0% and NMT 115.0% of the labeled amount of magnesium carbonate (MgCO3).
• A. Identification TestsGeneral, Calcium 191: The addition of 1 N hydrochloric acid to 1 Tablet produces effervescence, and the resulting solution, after having been filtered, meets the requirements of the tests.
• B. Identification TestsGeneral, Magnesium 191
Sample solution: Heat 2 Tablets in 20 mL of 1 N sulfuric acid. Cool, add 20 mL of alcohol, mix, and allow to stand for 30 min. Filter this solution, and add 2 mL of 1 N hydrochloric acid to the filtrate.
Acceptance criteria: Meet the requirements
• Calcium Carbonate
Sample solution: Finely powder NLT 20 Tablets. Transfer a portion of the powder, equivalent to 400 mg of calcium carbonate, to a beaker with the aid of 25 mL of water, and add 10 mL of 1 N hydrochloric acid. Heat on a steam bath for 30 min, allow to cool, and transfer to a 100-mL volumetric flask with the aid of water. Dilute with water to volume, mix, filter, and use the filtrate. [NoteReserve a portion of the filtrate for the Sample solution in the Magnesium Carbonate test. ]
Analysis: Transfer 20.0 mL of Sample solution to a suitable container. Dilute with water to 100 mL, and add 15 mL of 1 N sodium hydroxide, 5 mL of triethanolamine, and 100 mg of hydroxy naphthol blue. Titrate with 0.05 M edetate disodium VS until the solution is deep blue. Each mL of 0.05 M edetate disodium is equivalent to 5.004 mg of CaCO3.
Acceptance criteria: 90.0%110.0%
• Magnesium Carbonate
Sample solution: Use a portion of the filtrate from the Sample solution in the Calcium Carbonate test.
Analysis: Transfer the Sample solution equivalent to 120 mg of calcium carbonate and magnesium carbonate combined to a suitable container. Dilute with water to 100 mL, and add 10 mL of ammoniaammonium chloride buffer TS, 5 mL of triethanolamine, and 0.3 mL of eriochrome black TS. Titrate with 0.05 M edetate disodium VS to a blue endpoint. From the volume of 0.05 M edetate disodium consumed, subtract the volume of 0.05 M edetate disodium corresponding to the content of calcium carbonate in the portion of the Sample solution taken. The difference is the volume of 0.05 M edetate disodium equivalent to the quantity of magnesium carbonate present. Each mL of 0.05 M edetate disodium is equivalent to 4.216 mg of MgCO3.
Acceptance criteria: 85.0%115.0%
• Disintegration 701
Time: NMT 10 min, except that where Tablets are labeled as gelatin-coated, the time is NMT 30 min, simulated gastric fluid TS being substituted for water in the test
• Uniformity of Dosage Units 905: Meet the requirements for Weight Variation with respect to calcium carbonate and to magnesium carbonate
• 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:
Result = [(FM × M) × 0.8] + [(FC × C) × 0.9]
• Packaging and Storage: Preserve in well-closed containers.
• Labeling: Tablets that are gelatin-coated are so labeled.
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 2449Pharmacopeial Forum: Volume No. 27(6) Page 3256