Nitrofurazone Topical Solution

» Nitrofurazone Topical Solution contains not less than 95.0 percent and not more than 105.0 percent (w/w) of the labeled amount of C6H6N4O4.

[note—Avoid exposure at all times to direct sunlight, excessive heat, and alkaline materials. ]

Packaging and storage— Preserve in tight, light-resistant containers. Avoid exposure to direct sunlight and excessive heat.

USP Reference standards

—

USP Nitrofurazone RS

Identification— Dissolve 400 mg of potassium hydroxide in a mixture of 9.5 mL of alcohol and 0.5 mL of methanol. Immediately before use dilute with dimethylformamide to 100 mL. To 10 mL of this solution add 1 drop of Topical Solution: a purple solution results.

Assay— [note—Protect from light all solutions that contain nitrofurazone. ]

Triethylamine buffer, Mobile phase, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Nitrofurazone Ointment.

Assay preparation— Transfer an accurately measured portion of Topical Solution, equivalent to about 1 mg of nitrofurazone, to a 100-mL low actinic volumetric flask. Add 0.2 mL of dimethylformamide and about 25 mL of warm (between 40

and 50

) alcohol. Dilute with water to volume, and mix.

Procedure— Proceed as directed in the Assay under Nitrofurazone Ointment. Calculate the quantity, in mg, of C6H6N4O4 in the portion of Topical Solution taken by the formula:

100C(rU / rS)

in which C is the concentration, in mg per mL, of USP Nitrofurazone RS in the Standard preparation, and rU and rS are the nitrofurazone peak responses obtained from the Assay preparation and the Standard preparation, respectively.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Leonel M. Santos, Ph.D. Senior Scientific Liaison 1-301-816-8168	(SM12010) Monographs - Small Molecules 1
Reference Standards	RS Technical Services 1-301-816-8129 rstech@usp.org

USP35–NF30 Page 4064