Iodine Tincture
» Iodine Tincture contains, in each 100 mL, not less than 1.8 g and not more than 2.2 g of iodine (I), and not less than 2.1 g and not more than 2.6 g of sodium iodide (NaI).
Iodine Tincture may be prepared by dissolving 20 g of Iodine and 24 g of Sodium Iodide in 500 mL of Alcohol and then adding Purified Water to make the product measure 1000 mL.
Packaging and storage— Preserve in tight containers.
Identification—
A: Add 1 drop to a mixture of 1 mL of starch TS and 9 mL of water: a deep blue color is produced.
B: Evaporate a few mL on a steam bath to dryness: the residue responds to the flame test for Sodium 191, and to the tests for Iodide 191.
Alcohol content 611: between 44.0% and 50.0% of C2H5OH.
Assay for iodine— Proceed as directed in the Assay for iodine under Iodine Topical Solution, using 10 mL of Iodine Tincture.
Assay for sodium iodide— Proceed as directed in the Assay for sodium iodide under Iodine Topical Solution, using 10 mL of Iodine Tincture. The difference between the number of mL of 0.05 M potassium iodate used and half the number of mL of 0.1 N sodium thiosulfate used in the Assay for iodine, multiplied by 14.99, represents the number of mg of NaI in the volume of Iodine Tincture taken.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Jeanne H. Sun
Assistant Scientific Liaison
1-301-816-3361
(CMP2010) Compounding
USP35–NF30 Page 3516