Benzethonium Chloride Topical Solution
» Benzethonium Chloride Topical Solution contains not less than 95.0 percent and not more than 105.0 percent of the labeled amount of benzethonium chloride (C27H42ClNO2).
Packaging and storage Preserve in tight, light-resistant containers.
Identification The residue obtained by evaporating, on a steam bath, a volume of Topical Solution, equivalent to about 200 mg of benzethonium chloride, responds to the Identification tests under Benzethonium Chloride.
Oxidizing substances To 5 mL add 0.5 mL of potassium iodide TS and a few drops of 3 N hydrochloric acid: the solution does not acquire a yellow color.
Limit of nitrites To 1 drop of Topical Solution on a spot plate add 1 drop each of glacial acetic acid, sulfanilic acid in acetic acid (1 in 100), and 1-naphthylamineacetic acid solution (prepared by boiling 30 mg of 1-naphthylamine in 70 mL of water, decanting the colorless solution from the blue-violet residue, and mixing with 30 mL of glacial acetic acid): no red color develops in the resulting solution within 10 minutes.
Assay Transfer a volume of Topical Solution, equivalent to about 200 mg of benzethonium chloride, to a glass-stoppered flask, and proceed as directed in the Assay under Benzethonium Chloride, beginning with Add 0.4 mL of bromophenol blue solution (1 in 2000).
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USP35NF30 Page 2318Pharmacopeial Forum: Volume No. 27(5) Page 2979