Packaging and storage—
Preserve in tight containers.
Identification—
A:
Add 1 mL of an alcohol dilution of it containing about 0.05% of iodine to a mixture of 1 mL of starch TS and 9 mL of water: a deep blue color is produced.
B:
Place 10 g in a 50-mL beaker, avoiding contact with the walls of the beaker. Cover the mouth of the beaker with a disk of filter paper, and wet it with 1 drop of starch TS: no blue color appears within 60 seconds.
pH 
791
:
between 1.5 and 6.5, determined in a solution (1 in 20).
Assay—
Transfer an accurately weighed quantity of Ointment, equivalent to about 50 mg of iodine, to a 100-mL beaker, add water to make a total volume of not less than 30 mL, and stir until the ointment is dissolved. Titrate immediately with 0.02 N sodium thiosulfate VS, determining the endpoint potentiometrically, using a platinum-calomel electrode system. Perform a blank determination, and make any necessary correction. Each mL of 0.02 N sodium thiosulfate is equivalent to 2.538 mg of I.
