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Povidone-Iodine
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(C6H9NO)n·xI

2-Pyrrolidinone, 1-ethenyl-, homopolymer, compd. with iodine.
1-Vinyl-2-pyrrolidinone polymer, compound with iodine [25655-41-8].
» Povidone-Iodine is a complex of Iodine with Povidone. It contains not less than 9.0 percent and not more than 12.0 percent of available iodine (I), calculated on the dried basis.
Packaging and storage— Preserve in tight containers.
Identification—
A: Add 1 drop of a solution (1 in 10) to a mixture of 1 mL of starch TS and 9 mL of water: a deep blue color is produced.
B: Spread 1 mL of a solution (1 in 10) over an area of about 20 cm × 20 cm on a glass plate, and allow to air-dry at room temperature in an atmosphere of low humidity overnight: a brown, dry, non-smearing film is formed, and it dissolves readily in water.
Loss on drying 731— Dry 5.0 g of it at 105 until the difference between two successive weighings at 1-hour intervals is not greater than 5.0 mg: it loses not more than 8.0% of its weight.
Residue on ignition 281: not more than 0.025%, from 2 g.
Iodide ion—
Determination of total iodine— Dissolve about 500 mg of Povidone-Iodine, accurately weighed, in 100 mL of water in a 250-mL conical flask. Add sodium bisulfite TS until the color of iodine has disappeared. Add 25.0 mL of 0.1 N silver nitrate VS and 10 mL of nitric acid, and mix. Titrate the excess silver nitrate with 0.1 N ammonium thiocyanate VS, using ferric ammonium sulfate TS as the indicator. Perform a blank determination (see Residual Titrations under Titrimetry 541). Each mL of 0.1 N silver nitrate is equivalent to 12.69 mg of I. From the percentage of total iodine, calculated on the dried basis, subtract the percentage of available iodine (see Assay for available iodine), to obtain the percentage of iodide ion. Not more than 6.6%, calculated on the dried basis, is found.
Heavy metals, Method II 231: 0.002%.
Nitrogen content 461— Not less than 9.5% and not more than 11.5% of N is found, calculated on the dried basis.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay for available iodine— Place about 5 g of Povidone-Iodine, accurately weighed, in a 400-mL beaker, and add 200 mL of water. Cover the beaker, and stir by mechanical means at room temperature for not more than 1 hour to dissolve as completely as possible. Titrate immediately with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N sodium thiosulfate is equivalent to 12.69 mg of I.
Auxiliary Information— Staff Liaison : Behnam Davani, Ph.D., MBA, Senior Scientist
Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials
USP29–NF24 Page 1779
Pharmacopeial Forum : Volume No. 29(5) Page 1564
Phone Number : 1-301-816-8394