Iodine Topical Solution
»Iodine Topical Solution contains,in each 100mL,not less than 1.8g and not more than 2.2g of iodine (I),and not less than 2.1g and not more than 2.6g of sodium iodide (NaI).
Iodine 20g
Sodium Iodide 24g
Purified Water,a sufficient
quantity,to make		 1000mL
Dissolve the Iodine and the Sodium Iodide in 50mLof Purified Water,then add Purified Water to make 1000mL.
Packaging and storage— Preserve in tight,light-resistant containers,at a temperature not exceeding 35.
Identification—
A: Add 1drop to a mixture of 1mLof starch TSand 9mLof water:a deep blue color is produced.
B: Evaporate a few mLon a steam bath to dryness:the residue responds to the flame test for Sodium á191ñand to the tests for Iodide á191ñ.
Assay for iodine— Transfer 10.0mLof Topical Solution into a glass-stoppered,500-mLflask,and dilute with 10mLof water.Titrate with 0.1Nsodium thiosulfate VS,adding 3mLof starch TSas the endpoint is approached.Each mLof 0.1Nsodium thiosulfate is equivalent to 12.69mg of I.
Assay for sodium iodide— Transfer 10.0mLof Topical Solution to a glass-stoppered 500-mLflask,add 30mLof water and 50mLof hydrochloric acid,cool to room temperature,and titrate with 0.05Mpotassium iodate VSuntil the dark brown solution that is produced becomes pale brown.Add 1mLof amaranth TS,and continue the titration slowly until the red color just changes to yellow.The difference between the number of mLof 0.05Mpotassium iodate used and half the number of mLof 0.1Nsodium thiosulfate used in the Assay for iodine,multiplied by 14.99,represents the number of mg of NaIin the volume of Topical Solution taken.
Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1030
Phone Number:1-301-816-8394