Assay
Mobile phase
,
Standard preparation,and
Chromatographic systemProceed as directed in the
Assayunder
Isoniazid.
Assay preparation
Transfer an accurately measured volume of Injection,equivalent to about 100mg of isoniazid,to a 50-mLvolumetric flask.Dilute with Mobile phaseto volume,and mix.Transfer 8.0mLof this solution to a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Procedure
Proceed as directed for
Procedurein the
Assayunder
Isoniazid.Calculate the quantity,in mg,of C
6H
7N
3Oin each mLof the Injection taken by the formula:
312.5(C/V)(rU/rS),
in which
Cis the concentration,in mg per mL,of
USP Isoniazid RSin the
Standard preparation,Vis the volume,in mL,of Injection taken,and
rUand
rSare the peak responses of isoniazid obtained from the
Assay preparationand the
Standard preparation,respectively.