Color and clarity
Standard solution
Transfer 2.0mLof 0.100Niodine VSto a 500-mLvolumetric flask,dilute with water to volume,and mix.
Procedure
Visually examine a portion of the Injection (Test solution)in a suitable clear glass test tube against a white background:it is not pinkish and it contains no precipitate.If any yellow color is observed in the Test solution,concomitantly determine the absorbances of the Test solutionand the Standard solutionin 1-cm cells with a suitable spectrophotometer set at 460nm:the absorbance of the Test solutiondoes not exceed that of the Standard solution.
Assay
Mobile phase
To 1liter of 0.05
Mmonobasic sodium phosphate add about 519mg of sodium 1-octanesulfonate and about 45mg of edetate disodium,and mix.Adjust by the dropwise addition of phosphoric acid,if necessary,to a pHof 3.8.Mix 85volumes of this solution with 15volumes of methanol.Make adjustments if necessary (see
System Suitabilityunder
Chromatography á621ñ).
Standard preparation
Dissolve an accurately weighed quantity of
USP Epinephrine Bitartrate RSin
Mobile phase,and dilute quantitatively,and stepwise if necessary,with
Mobile phaseto obtain a solution having a known concentration of about 0.1mg of epinephrine per mL.
Assay preparation
Transfer an accurately measured volume of Injection,equivalent to about 1mg of epinephrine,to a 10-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
System suitability preparation
Dissolve 10mg of dopamine hydrochloride in 100mLof the Standard preparation,and mix.
Chromatographic system
(see
Chromatography á621ñ)The liquid chromatograph is equipped with a 280-nm detector and a 4.6-mm ×15-cm column that contains packing L7.The flow rate is about 2mLper minute.Chromatograph the
Standard preparationand the
System suitability preparation,and record the peak responses as directed under
Procedure:the resolution,
R,between the epinephrine and dopamine hydrochloride peaks is not less than 3.5,and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure
Separately inject equal volumes (about 20µL)of the
Standard preparationand the
Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.The relative retention times are about 1.0for epinephrine and 2.0for dopamine hydrochloride.Calculate the quantity,in mg,of C
9H
13NO
3in each mLof the Injection taken by the formula:
(183.20/333.29)(10)(C/V)(rU/rS),
in which 183.20and 333.29are the molecular weights of epinephrine and epinephrine bitartrate,respectively;
Cis the concentration,in mg per mL,of
USP Epinephrine Bitartrate RSin the
Standard preparation;Vis the volume,in mL,of Injection taken;and
rUand
rSare the peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.