Potassium Iodide Tablets
» Potassium Iodide Tablets contain not less than 94.0 percent and not more than 106.0 percent of the labeled amount of KI for Tablets of 300 mg or more, and not less than 92.5 percent and not more than 107.5 percent for Tablets of less than 300 mg.
Packaging and storage— Preserve in tight containers.
Identification— A filtered solution of powdered Tablets responds to the tests for Potassium 191 and for Iodide 191.
Dissolution 711
For Uncoated Tablets
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Time: 15 minutes.
Procedure— Determine the amount of KI dissolved from UV absorbances at the wavelength of maximum absorbance at about 227 nm of filtered portions of the solutions under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of potassium iodide in the same medium.
Tolerances— Not less than 75% (Q) of the labeled amount of KI is dissolved in 15 minutes.
Uniformity of dosage units 905: meet the requirements.
Assay— Weigh and finely powder not less than 20 Tablets. Transfer a portion of the powder, equivalent to about 1.2 g of potassium iodide, to a 250-mL volumetric flask, add 100 mL of water, shake for 20 minutes, dilute with water to volume, and mix. Filter through paper, discarding the first 20 mL of the filtrate. Transfer 100.0 mL of the filtrate, 25 mL of alcohol, and 1.0 mL of 1 N nitric acid to a 200-mL beaker. Titrate with 0.1 N silver nitrate VS, determining the endpoint potentiometrically, using silver-calomel electrodes and a salt bridge containing 4 percent agar in a saturated potassium nitrate solution. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N silver nitrate is equivalent to 16.60 mg of KI.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Leonel M. Santos, Ph.D.
Senior Scientific Liaison
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711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
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USP35–NF30 Page 4373