Identification
C:
The chromatogram of the
Assay preparationobtained as directed in the
Assay for epinephrineexhibits a major peak for epinephrine,the retention time of which corresponds to that exhibited in the chromatogram of the
Standard preparationobtained as directed in the
Assay for epinephrine.
Assay for prilocaine hydrochloride
Assay preparation
Transfer an accurately measured volume of Injection,equivalent to about 200mg of prilocaine hydrochloride,to a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Procedure
[NOTEUse peak areas where peak responses are indicated.
]Separately inject equal volumes (about 10µL)of the
Assay preparationand the
Standard preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of prilocaine hydrochloride (C
13H
20N
2O·HCl)in each mLof the Injection taken by the formula:
50(C/V)(rU/rS),
in which
Cis the concentration,in mg per mL,of
USP Prilocaine Hydrochloride RSin the
Standard preparation,
Vis the volume,in mL,of Injection taken,and
rUand
rSare the prilocaine peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.
Assay for epinephrine
Mobile phase
Mix 50mLof glacial acetic acid and 930mLof water,and adjust with 1Nsodium hydroxide to a pHof 3.40.Dissolve 1.1g of sodium 1-heptanesulfonate in this solution,add 1.0mLof 0.1
Mdisodium ethylenediaminetetraacetate,and mix.Mix about 9volumes of this solution with 1volume of methanol.Filter through a membrane filter (1µm or finer porosity),and degas.Make adjustments if necessary (see
System Suitabilityunder
Chromatography á621ñ).
Standard preparation
Dissolve an accurately weighed quantity of
USP Epinephrine Bitartrate RSin
Mobile phaseto obtain a solution having a known concentration of about 9µg of epinephrine bitartrate per mL.Pipet 10mLof this solution into a 50-mLvolumetric flask,dilute with
Mobile phaseto volume,and mix to obtain a
Standard preparationhaving a known concentration of about 1.8µg of epinephrine bitartrate per mL.
Assay preparation
Transfer an accurately measured volume of Injection,equivalent to about 50µg of epinephrine,to a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Chromatographic system
(see
Chromatography á621ñ)The liquid chromatograph is fitted with a 30-cm ×3.9-mm stainless steel column packed with packing L1,and is equipped with an electrochemical detector held at a potential of +650mV,a controller capable of regulating the background current,and a suitable recorder,and it is operated at a temperature between 20

and 25

maintained at ±1.0

of the selected temperature.The flow rate is about 1mLper minute.Chromatograph the
Standard preparationas directed for
Procedure:the relative standard deviation of the peak responses of successive injections of the
Standard preparationis not more than 1.5%.
Procedure
Separately inject equal volumes (about 20µL)of the
Assay preparationand the
Standard preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in µg,of epinephrine (C
9H
13NO
3)in each mLof the Injection taken by the formula:
(183.21/333.30)50(C/V)(rU/rS),
in which 183.21and 333.30are the molecular weights of epinephrine and epinephrine bitartrate,respectively,
Cis the concentration,in µg 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.