» Fluorouracil Cream contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of fluorouracil (C4H3FN2O2). It may contain Sodium Hydroxide to adjust the pH.
Packaging and storage Preserve in tight containers, and store at controlled room temperature.
USP Reference standards 11
Identification Prepare a test solution by placing a quantity of Cream, equivalent to about 5 mg of fluorouracil, in a glass-stoppered conical flask, add 50 mL of alcohol, and shake until dissolved. Dissolve 5 mg of USP Fluorouracil RS in 50 mL of alcohol to obtain a Standard solution. In 20-µL increments, apply 100 µL each of the Standard solution and the test solution to a line about 3 cm from the bottom edge of a thin-layer chromatographic plate coated with a 0.25-mm layer of chromatographic silica gel mixture, which previously has been dried and activated at 105 for 5 minutes. Develop the chromatogram in a solvent system consisting of a mixture of ethyl acetate, methanol, and ammonium hydroxide (75:25:1), allowing the solvent front to move about 15 cm beyond the initial spotting line. Remove the plate, air-dry for 15 minutes, and examine under short-wavelength UV light: the RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Microbial enumeration tests 61 and Tests for specified microorganisms 62 It meets the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa.
Minimum fill 755: meets the requirements.
Mobile phase , Standard preparation, and Chromatographic systemProceed as directed in the Assay under Fluorouracil.
Assay preparation Transfer an accurately weighed portion of Cream, equivalent to about 10 mg of fluorouracil, to a 100-mL volumetric flask, add 20 mL of methanol, and mix on a vortex mixer to dissolve. Dilute with water to volume, and mix. Transfer 1.0 mL of this solution to a 10-mL volumetric flask, dilute with water to volume, mix, and filter.
Procedure Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of fluorouracil (C4H3FN2O2) in the portion of Cream taken by the formula:
C(rU / rS)in which C is the concentration, in µg per mL, of USP Fluorouracil RS in the Standard preparation; and rU and rS are the fluorouracil peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 3240