Assay
Phosphate buffer, Mobile phase, Standard preparation, Resolution solution, and Chromatographic system
Proceed as directed in the
Assay under
Cytarabine.
Assay preparation
Separately constitute 5 vials of Cytarabine for Injection in a volume of water, accurately measured, corresponding to the volume specified in the labeling. Pool and mix the constituted solutions in a suitable container. Transfer an accurately measured volume of the constituted solution, equivalent to about 100 mg of cytarabine, to a 100-mL volumetric flask, dilute with water to volume, and mix.
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 C
9H
13N
3O
5 in the portion of constituted solution taken by the formula:
1000C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Cytarabine RS in the
Standard preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.