Packaging and storage— Preserve in tight, light-resistant containers. Store at room temperature.

Labeling— The label states that this article is not intended for direct administration to humans or animals.

Identification— Evaporate a volume of Concentrate, equivalent to about 200 mg of benzethonium chloride, on a steam bath: the residue so obtained meets the requirements of the tests for Identification under Benzethonium Chloride.

Oxidizing substances— To 5 mL of Concentrate 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 Concentrate on a spot plate add 1 drop each of glacial acetic acid, sulfanilic acid in acetic acid solution (1 in 100), and 1-naphthylamine–acetic 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 Concentrate, 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).”

Topic/Question	Contact	Expert Committee
Monograph	Behnam Davani, Ph.D., M.B.A. Senior Scientist 1-301-816-8394	(MDAA05) Monograph Development-Antivirals and Antimicrobials

USP32–NF27 Page 1639