Dopamine Hydrochloride Injection
»Dopamine Hydrochloride Injection is a sterile solution of Dopamine Hydrochloride in Water for Injection.It contains not less than 95.0percent and not more than 105.0percent of the labeled amount of C8H11NO2·HCl.It may contain a suitable antioxidant.
NOTE—Do not use the Injection if it is darker than slightly yellow or discolored in any other way.
Packaging and storage— Preserve in single-dose containers of Type Iglass.
Labeling— Label it to indicate that the Injection is to be diluted with a suitable parenteral vehicle prior to intravenous infusion.
Identification— Transfer a volume of Injection to a suitable container,and dilute if necessary,with dilute methanol (1in 5)to obtain a test solution having a known concentration of 1.6mg per mL.Prepare a Standard solution of USP Dopamine Hydrochloride RSin dilute methanol (1in 5)having the same concentration as the test solution.The test solution so obtained responds to the Thin-layer Chromatographic Identification Test á201ñ,a mixture of n-butyl alcohol,glacial acetic acid,and water (4:1:1)being used as the developing solvent and 5µLeach of the test solution and Standard solution being applied to the thin-layer chromatographic plate.
Bacterial endotoxins á85ñ— It contains not more than 16.67USP Endotoxin Units per mg of dopamine hydrochloride.
pHá791ñ: between 2.5and 5.0.
Particulate matter á788ñ: meets the requirements for small-volume injections.
Other requirements— It meets the requirements under Injections á1ñ.
Assay—
Mobile phase— Prepare a filtered and degassed mixture of 0.005Msodium 1-octanesulfonate in 1%glacial acetic acid and acetonitrile (87:13).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation— Dissolve a suitable quantity of USP Dopamine Hydrochloride RS,accurately weighed,in Mobile phaseto obtain a solution having a concentration of about 1.6mg per mL.Pipet 10mLof this solution into a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix to obtain a Standard preparationhaving a known concentration of about 0.16mg of dopamine hydrochloride per mL.
System suitability solution— Prepare a solution of benzoic acid in methanol containing about 20mg per mL.Dilute 1volume of this solution with 3volumes of the Mobile phaseto obtain a solution having a final concentration of about 5mg per mL.Transfer 10.0mLof this solution and 10.0mLof a Standard solution containing 1.6mg of USP Dopamine Hydrochloride RSper mLto a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Assay preparation— Transfer an accurately measured volume of Injection,equivalent to about 16mg of dopamine hydrochloride,to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 280-nm detector and a 4-mm ×30-cm column packed with packing L1.The flow rate is about 1.5mLper minute.Chromatograph the System suitability solution,and record the peak responses as directed under Procedure:the resolution,R,between benzoic acid and dopamine hydrochloride is not less than 4.0.Chromatograph the Standard preparation,and record the peak responses as directed under Procedure:the relative standard deviation for replicate injections is not more than 3.0%.
Procedure— Separately inject equal volumes (about 40µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C8H11NO2·HCl in each mLof the Injection taken by the formula:
(100C/V)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Dopamine Hydrochloride RSin the Standard preparation;Vis the volume,in mL,of Injection taken;and rUand rSare the responses of dopamine hydrochloride obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 690
Phone Number:1-301-816-8305