Dobutamine for Injection
»Dobutamine for Injection is a sterile mixture of Dobutamine Hydrochloride with suitable diluents.It contains an amount of dobutamine hydrochloride equivalent to not less than 90.0percent and not more than 110.0percent of the labeled amount of dobutamine (C18H23NO3).
[Caution—Great care should be taken to prevent inhaling particles of Dobutamine for Injection and exposing the skin to it.Protect the eyes. ]
Packaging and storage— Preserve in Containers for Sterile Solidsas described under Injections á1ñ,at controlled room temperature.
Constituted solution— At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ.Do not use the constituted solution if it is brown or contains a precipitate.
Identification— Prepare a solution in methanol,clarified by centrifugation,to contain 10mg of dobutamine hydrochloride per mL.Apply 10µLof this solution and 10µLof a freshly prepared Standard solution of USP Dobutamine Hydrochloride RSin methanol containing 10mg per mLto a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Allow the spots to dry,and develop the chromatogram in a solvent system consisting of a mixture of ethyl acetate,n-propyl alcohol,water,and glacial acetic acid (100:40:15:5)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the developing chamber,mark the solvent front,and allow the solvent to evaporate at room temperature.Observe the plate under short-wavelength UVlight:the RFvalue of the principal spot obtained from the solution under test corresponds to that obtained from the Standard solution.
Bacterial endotoxins á85ñ— It contains not more than 5.56USP Endotoxin Units per mg of dobutamine.
Uniformity of dosage units á905ñ: meets the requirements.
pHá791ñ: between 2.5and 5.5,the contents of 1vial being dissolved in 10mLof water.
Particulate matter á788ñ: meets the requirements for small-volume injections.
Other requirements— It meets the requirements under Injections á1ñ.
Assay—
Ion-pair solution,Mobile phase,System suitability solution,Standard preparation,andChromatographic system— Proceed as directed in the Assayunder Dobutamine Injection.
Assay preparation— Inject about 10mLof Mobile phaseinto 1vial of Dobutamine for Injection,taking care not to let pressure build up in the vial.Shake to dissolve the specimen completely.Transfer the solution to an appropriate volumetric flask,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a concentration of 0.5mg of dobutamine per mL.
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.Calculate the quantity,in mg,of C18H23NO3in each container of Dobutamine for Injection taken by the formula:
(301.39/337.84)(10CD)(rU/rS),
in which 301.39and 337.84are the molecular weights of dobutamine and dobutamine hydrochloride,respectively;Cis the concentration,in mg per mL,of USP Dobutamine Hydrochloride RSin the Standard preparation;Dis the dilution factor in the Assay preparation;and rUand rSare the peak responses 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 682
Phone Number:1-301-816-8305