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Carbamide Peroxide Topical Solution
»Carbamide Peroxide Topical Solution is a solution in anhydrous glycerin of Carbamide Peroxide or of carbamide peroxide prepared from hydrogen peroxide and Urea.It contains not less than 78.0percent and not more than 110.0percent,by weight,of the labeled amount of CH6N2O3.
Packaging and storage—
Preserve in tight,light-resistant containers,and avoid exposure to excessive heat.
Identification—
A:
Mix 1mLwith 1mLof nitric acid:a white,crystalline precipitate is formed.
B:
It responds to the tests for Peroxide á191ñ.
Specific gravity á841ñ:
between 1.245and 1.272.
pHá791ñ:
between 4.0and 7.5.
Assay—
Transfer an accurately weighed quantity of Topical Solution,equivalent to about 100mg of carbamide peroxide,to a 500-mLiodine flask with the aid of 25mLof water,add 5mLof glacial acetic acid,and mix.Add 2g of potassium iodide and 1drop of ammonium molybdate TS,and allow to stand in the dark for 10minutes.Titrate the liberated iodine with 0.1Nsodium thiosulfate VS,adding 3mLof starch TSas the endpoint is approached.Each mLof 0.1Nsodium thiosulfate is equivalent to 4.704mg of CH6N2O3.
Auxiliary Information—
Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(PA1)Pharmaceutical Analysis 1
USP28–NF23Page 345
Phone Number:1-301-816-8379
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