Povidone-Iodine Mouthwash

Disinfectant.

Povidone-Iodine Mouthwash is either an aqueous solution of Iodinated Povidone or it is prepared by the interaction between Iodine and Povidone.

The mouthwash complies with the requirements stated under Oromucosal Preparations and with the following requirements.

0.085 to 0.120% w/v.

A yellowish-brown solution.

A. Dilute 1 mL to 2 mL with water and add 1 mL of the resulting solution to a mixture of 1 mL of starch mucilage and 9 mL of water. A deep blue colour is produced.

B. Transfer 10 mL to a small flask and cover the mouth of the flask with filter paper moistened with 0.05 mL of starch mucilage. No blue colour is produced on the paper within 60 seconds.

C. To 10 mL add drop wise 0.1m sodium thiosulfate until the colour of the iodine is just discharged. To 5 mL of the solution add 10 mL of 1m hydrochloric acid and 5 mL of a 7.0% w/v solution of potassium dichromate. A red precipitate is produced.

D. To 5 mL add 2 mL of ammonium cobaltothiocyanate solution previously acidified with 5m hydrochloric acid. A blue precipitate is produced.

pH, 3.0 to 6.5, Appendix V L.

Not more than 0.06% w/v when determined by the following method. To 50 mL of the mouthwash add sodium metabisulfite until the colour of iodine has disappeared. Add 25 mL of 0.1m silver nitrate VS, 10 mL of nitric acid and 5 mL of ferric ammonium sulfate solution R2. Titrate with 0.1m ammonium thiocyanate VS. Repeat the procedure without the solution being examined. Each mL of 0.1m silver nitrate VS is equivalent to 12.69 mg of total iodine. Calculate the percentage content of total iodine and subtract the percentage content of available iodine determined in the Assay to obtain the percentage content of iodide.

To 100 mL add 10 mL of 0.1m hydrochloric acid and sufficient water to produce 150 mL and titrate with 0.1m sodium thiosulfate VS determining the end point potentiometrically. Each mL of 0.1m sodium thiosulfate VS is equivalent to 12.690 mg of I.