» Furazolidone contains not less than 97.0 percent and not more than 103.0 percent of C8H7N3O5, calculated on the dried basis.
Packaging and storage Preserve in tight, light-resistant containers, and avoid exposure to direct sunlight.
A: Infrared Absorption 197K: previously dried.
B: Ultraviolet Absorption 197U
Solution: 10 µg per mL.
C: Add about 50 mg to 10 mL of a freshly prepared mixture of dimethylformamide and alcoholic potassium hydroxide TS (9:1): the solution becomes purple, immediately changes to deep blue, and, upon standing for 10 minutes, again turns purple.
Loss on drying 731 Dry it at 100 for 1 hour: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.25%.
Assay Transfer about 100 mg of Furazolidone, accurately weighed, to a 250-mL volumetric flask, dilute with dimethylformamide to volume, and mix. Transfer 5.0 mL of this solution to a 250-mL volumetric flask, dilute with water to volume, and mix (assay solution). Similarly, dissolve a suitable quantity of USP Furazolidone RS, accurately weighed, in dimethylformamide to obtain a Standard stock solution having a known concentration of about 400 µg per mL. Transfer 5.0 mL of this stock solution to a 250-mL volumetric flask, dilute with water to volume, and mix (Standard solution). Concomitantly determine the absorbances of the assay solution and the Standard solution at the wavelength of maximum absorbance at about 367 nm, with a suitable spectrophotometer, using dimethylformamide solution (1 in 50) as the blank. Calculate the quantity, in mg, of C8H7N3O5 in the Furazolidone taken by the formula:
12.5C(AU / AS)in which C is the concentration, in µg per mL, of USP Furazolidone RS in the Standard solution; and AU and AS are the absorbances of the assay solution and the Standard solution, respectively.
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USP32NF27 Page 2459