Assay
Phosphate buffer,Mobile phase,Standard preparation,Resolution solution,and Chromatographic system
Proceed as directed in the
Assayunder
Cytarabine.
Assay preparation
Separately constitute 5vials of Cytarabine for Injectionin 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 100mg of cytarabine,to a 100-mLvolumetric flask,dilute with water to volume,and mix.
Procedure
Separately inject equal volumes (about 10µL)of the
Standard preparationand the
Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C
9H
13N
3O
5in the portion of constituted solution taken by the formula:
1000C(rU/rS),
in which
Cis the concentration,in mg per mL,of
USP Cytarabine RSin the
Standard preparation;and
rUand
rSare the peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.