A: Infrared Absorption 197K.

B: Ultraviolet Absorption 197U—

C: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

Test solution: 30 mg per mL, in water.

Mobile phase and Chromatographic system— Proceed as directed in the Assay.

Standard solution— Use the Standard preparation prepared as directed in the Assay.

Test solution— Use the Assay preparation.

Procedure— Proceed as directed in the Assay. Calculate the percentages of trifluridine related compound A and 5-(trifluoromethyl)uracil in the portion of Trifluridine taken by the formula: in which C is the concentration, in mg per mL, of USP Trifluridine Related Compound A RS and 5-(trifluoromethyl)uracil in the Standard solution; W is the weight, in mg, of Trifluridine taken; and rU and rS are the peak responses for the related compounds obtained from the Test solution and the Standard solution, respectively: not more than 1.0% of each related compound is found.

Mobile phase— Prepare a filtered and degassed 0.15% sodium citrate solution and adjust with 1 N hydrochloric acid to a pH of 6.8. Make adjustments if necessary (see System Suitability under Chromatography 621).

Standard stock preparation— Dissolve accurately weighed quantities of USP Trifluridine RS, USP Trifluridine Related Compound A RS, and 5-(trifluoromethyl)uracil in water to obtain a solution having known concentrations of about 1 mg per mL, 0.01 mg per mL, and 0.01 mg per mL, respectively. [note—This stock preparation may be stored at 0 to 5 for 3 months.]

Standard preparation— Transfer 10.0 mL of the Standard stock preparation to a 50-mL volumetric flask, dilute with water to volume, and mix.

Assay preparation— Transfer about 50 mg of Trifluridine, accurately weighed, to a 250-mL volumetric flask, dissolve in and dilute with water to volume, and mix.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 254-nm detector and a 4.2-mm × 25-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the resolution, R, between 5-(trifluoromethyl)uracil and trifluridine related compound A is not less than 3.0 and between trifluridine related compound A and trifluridine is not less than 4.0; and the relative standard deviation for replicate injections is not more than 2.0%.

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 areas for the major peaks. Calculate the quantity, in mg, of C10H11F3N2O5 in the portion of Trifluridine taken by the formula: in which C is the concentration, in mg per mL, of USP Trifluridine RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.