Assay
[NOTEUse low-actinic glassware throughout this assay,and otherwise protect the solutions from exposure to light.
]
Mobile phase
Prepare a suitable degassed mixture of dehydrated alcohol and water (95:5).
Standard preparation
Dissolve an accurately weighed quantity of
USP Phytonadione RSin
Mobile phaseto obtain a solution having a known concentration of about 1mg per mL.Pipet 1mLof this solution into a 10-mLvolumetric flask,dilute with
Mobile phaseto volume,and mix to obtain a
Standard preparationhaving a known concentration of about 0.1mg per mL.
Assay preparation for Injection containing 10mg or more of phytonadione per mL
Pipet a volume of Injection,equivalent to 10mg of phytonadione,into a 10-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Pipet 1mLof this solution into a 10-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Assay preparation for Injection containing less than 10mg of phytonadione per mL
Pipet a volume of Injection,equivalent to 1mg of phytonadione,into a 10-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Chromatographic system(see Chromatography á621ñ)
The liquid chromatograph is equipped with a 254-nm detector and a 4-mm ×25-cm column that contains packing L1.The flow rate is about 0.7mLper minute.Chromatograph five replicate injections of the
Standard preparation,and record the peak responses as directed for
Procedure:the relative standard deviation is not more than 1.5%.
Procedure
Separately inject equal volumes (about 10µL)of the
Standard preparationand the
Assay preparationinto the chromatograph,record the chromatograms,and measure the peak response for the major peak.Calculate the quantity,in mg,of C
31H
46O
2in each mLof the Injection taken by the formula:
D(C/V)(rU/rS),
in which
Dis 100if the Injection contains 10mg or more of phytonadione per mL,or 10if the Injection contains less than 10mg of phytonadione per mL,
Cis the concentration,in mg per mL,of
USP Phytonadione RSin the
Standard preparation;Vis the volume,in mL,of Injection taken;and
rUand
rSare the peak responses of phytonadione obtained from the
Assay preparationand the
Standard preparation,respectively.