(Ph. Eur. monograph 1142)
Action and use
Antiseptic.
Preparations
Povidone-Iodine Eye Drops
Povidone-Iodine Mouthwash
Povidone-Iodine Solution
DEFINITION
Complex of iodine and povidone.
Content
9.0 per cent to 12.0 per cent of available iodine (dried substance).
PRODUCTION
It is produced using povidone that complies with the monograph on Povidone (0685), except that the povidone used may contain not more than 2.0 per cent of formic acid and not more than 8.0 per cent of water.
CHARACTERS
Appearance
Yellowish-brown or reddish-brown, amorphous powder.
Solubility
Soluble in water and in ethanol (96 per cent), practically insoluble in acetone.
IDENTIFICATION
A. Infrared absorption spectrophotometry (2.2.24).
Comparison: iodinated povidone CRS.
B. Dissolve 10 mg in 10 mL of water R and add 1 mL of starch solution R. An intense blue colour is produced.
TESTS
pH (2.2.3)
1.5 to 5.0.
Dissolve 1.0 g in 10 mL of carbon dioxide-free water R.
Iodide
Maximum 6.0 per cent (dried substance).
Dissolve 0.500 g in 100 mL of water R. Add sodium metabisulfite R until the colour of the iodine has disappeared. Add 25.0 mL of 0.1 M silver nitrate, 10 mL of nitric acid R and 5 mL of ferric ammonium sulfate solution R2. Titrate with 0.1 M ammonium thiocyanate. Carry out a blank titration.
1 mL of 0.1 M silver nitrate is equivalent to 12.69 mg of total iodine. From the percentage of total iodine, calculated with reference to the dried substance, subtract the percentage of available iodine as determined in the assay to obtain the percentage of iodide.
Loss on drying (2.2.32)
Maximum 8.0 per cent, determined on 0.500 g by drying in an oven at 105 °C for 3 h.
Sulfated ash (2.4.14)
Maximum 0.1 per cent, determined on 1.0 g.
ASSAY
Transfer 1.000 g into a ground-glass-stoppered flask containing 150 mL of water R and stir for 1 h. Add 0.1 mL of dilute acetic acid R and titrate with 0.1 M sodium thiosulfate using starch solution R as indicator.
1 mL of 0.1 M sodium thiosulfate is equivalent to 12.69 mg of available iodine.
STORAGE
Protected from light.
