U.S. PHARMACOPEIA

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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 90.0 percent and not more than 110.0 percent 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 Solids as described under Injections 1, at controlled room temperature.
Constituted solution— At the time of use, it meets the requirements for Constituted Solutions under Injections 1. 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 10 mg of dobutamine hydrochloride per mL. Apply 10 µL of this solution and 10 µL of a freshly prepared Standard solution of USP Dobutamine Hydrochloride RS in methanol containing 10 mg per mL to a thin-layer chromatographic plate (see Chromatography 621) 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 UV light: the RF value of the principal spot obtained from the solution under test corresponds to that obtained from the Standard solution.
Bacterial endotoxins 85 It contains not more than 5.56 USP Endotoxin Units per mg of dobutamine.
Uniformity of dosage units 905: meets the requirements.
pH 791: between 2.5 and 5.5, the contents of 1 vial being dissolved in 10 mL of water.
Particulate matter 788: meets the requirements for small-volume injections.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Other requirements— It meets the requirements under Injections 1.
Assay—
Ion-pair solution, Mobile phase, System suitability solution, Standard preparation, and Chromatographic system Proceed as directed in the Assay under Dobutamine Injection.
Assay preparation— Inject about 10 mL of Mobile phase into 1 vial 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 phase to obtain a solution having a concentration of 0.5 mg of dobutamine per mL.
Procedure— Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C18H23NO3 in each container of Dobutamine for Injection taken by the formula:
(301.39 / 337.84)(10CD)(rU / rS),
in which 301.39 and 337.84 are the molecular weights of dobutamine and dobutamine hydrochloride, respectively; C is the concentration, in mg per mL, of USP Dobutamine Hydrochloride RS in the Standard preparation; D is the dilution factor in the Assay preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Andrzej Wilk, Ph.D., Senior Scientific Associate
Expert Committee : (MDCV05) Monograph Development-Cardiovascular
USP29–NF24 Page 745
Phone Number : 1-301-816-8305