Procedure
Proceed as directed in
Chromatographic purity for
Gemcitabine Hydrochloride.Calculate the amount of cytosine expressed as a percentage of Gemcitabine Hydrochloride by the formula:
0.1(263.20/299.66)(CcV/L)(rt /rs )
in which 263.20and 299.66are the molecular weights of gemcitabine and gemcitabine hydrochloride,respectively;
Ccis the concentration of USP Cytosine RSin the
Standard solution,in µg per mL;
Vis the volume,in mL,of water used to reconstitute the vial;
Lis the labeled amount of gemcitabine in the vial,in mg;
rtis the peak response for cytosine in the
Test solution;and
rsis the response for cytosine in the
Standard solution:not more than 0.1%of cytosine is found.Similarly,calculate the amount of each impurity other than cytosine,expressed as a percentage of gemcitabine hydrochloride,by the formula:
0.1(263.20/299.66)(CsV/L)(ri/rs)
in which 263.20and 299.66are the molecular weights of gemcitabine and gemcitabine hydrochloride,respectively;
Csis the concentration of USP Gemcitabine Hydrochloride RSin the
Standard solution,in µg per mL;
Vis the volume,in mL,of water used to reconstitute the vial,
Lis the labeled amount of gemcitabine in the vial,in mg;
riis the response for gemcitabine
a-anomer or any other individual impurity;and
rsis the peak response for gemcitabine in the
Test solution.Not more than 0.1%of gemcitabine
a-anomer is found;not more than 0.2%each of any other impurity is found;and the sum of all impurities is not more than 0.3%.Exclude from the sum of all impurities any peaks that are below the limit of quantitation (0.02%).