Furazolidone Oral Suspension
» Furazolidone Oral Suspension is a suspension of Furazolidone in a suitable aqueous vehicle. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of furazolidone (C8H7N3O5).
Packaging and storage Preserve in tight, light-resistant containers, and avoid exposure to excessive heat.
Identification Add a quantity of Oral Suspension, equivalent to about 50 mg of furazolidone, to 10 mL of a freshly prepared mixture of dimethylformamide and alcoholic potassium hydroxide TS (9:1): the solution turns purple, immediately changes to deep blue, and, upon standing for 10 minutes, again turns purple.
pH 791: between 6.0 and 8.5.
Assay Transfer an accurately measured volume of Oral Suspension, equivalent to about 160 mg of furazolidone, to a suitable flask. Add 5 mL of water, and mix. Transfer the mixture with the aid of dimethylformamide to a 1000-mL volumetric flask. Add about 500 mL of dimethylformamide, shake by mechanical means for 10 minutes, dilute with dimethylformamide to volume, and mix. Transfer 5.0 mL of this solution to a 100-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 160 µg per mL. Transfer 5.0 mL of this stock solution to a 100-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 20) as the blank. Calculate the quantity, in mg, of furazolidone (C8H7N3O5) in each mL of the Oral Suspension taken by the formula:
20(C / V)(AU / AS)in which C is the concentration, in µg per mL, of USP Furazolidone RS in the Standard solution; V is the volume, in mL, of Oral Suspension taken; and AU and AS are the absorbances of the assay solution and the Standard solution, respectively.
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USP32NF27 Page 2459