Packaging and storage—
Preserve in single-dose containers, preferably of Type II glass, or of a suitable plastic material, and store at room temperature, avoid excessive heat, and protect from freezing.
Labeling—
The label states the total osmolar concentration in mOsmol per L.
Identification—
A:
The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
B:
It meets the requirements for the
Identification test under
Dextrose.
Chromatographic purity—
Phosphate buffer, Mobile phase, Standard preparation, System suitability solution, and Chromatographic system—
Proceed as directed in the
Assay under
Dobutamine Hydrochloride.
Test solution—
Transfer an accurately measured portion of Dobutamine in Dextrose Injection, equivalent to about 44.6 mg of dobutamine to a 100-mL volumetric flask, dilute with water to volume, and mix.
Procedure—
Inject a volume (about 20 µL) of the
Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of each impurity, excluding 5-hydroxymethylfurfural from all calculations, in the portion of Dobutamine in Dextrose Injection taken by the formula:
100(ri / rs),
in which
ri is the peak response for each impurity; and
rs is the sum of the responses of all of the peaks: not more than 1.0% of any individual impurity is found, and not more than 2.0% of the total impurities is found.
Limit of 5-hydroxymethylfurfural—
Ion-exchange column—
Fill an 8-mm chromatographic tube to a height of about 40 mm with a 100- to 200-mesh, strongly acidic, styrene-divinylbenzene cation-exchange resin. Wash the column with about 30 mL of water, discarding the eluate. [NOTE—Prepare a new column for each Test solution and Blank solution, and use each column only once.]
Test solution—
Transfer 2 mL of Injection to the ion-exchange column, and collect the eluate in a 50-mL volumetric flask. Pass 25 mL of water through the column, and collect the eluate in the same volumetric flask. Dilute the eluate with water to volume, and mix. Remove the stopper from the flask, and allow the solution to stand for about 30 minutes in order to oxidize any bisulfite ions present. The solution so obtained is the Test solution.
Blank solution—
Prepare a Blank solution in a similar manner to the Test solution by passing 27 mL of water through an ion-exchange column, and collecting the eluate in a 50-mL volumetric flask. Dilute with water to volume, and mix.
Procedure—
Determine the absorbance of the Test solution in a 1-cm cell at 284 nm, with a suitable spectrophotometer, after correcting for the Blank solution: the absorbance is not more than 0.25.
Other requirements—
It meets the requirements under
Injections 
1
.
Assay for dextrose—
Determine the angular rotation of Injection (see
Optical Rotation 781). Calculate the percentage (g per 100 mL) of dextrose (C
6H
12O
6·H
2O) in the portion of Injection taken by the formula:
(100/52.9)(198.17/180.16)AR,
in which 100 is the percentage; 52.9 is the midpoint of the specific rotation range for anhydrous dextrose, in degrees; 198.17 and 180.16 are the molecular weights for dextrose monohydrate and anhydrous dextrose, respectively;
A is 100 mm divided by the length of the polarimeter tube, in mm; and
R is the observed rotation, in degrees.
Assay for dobutamine—
Phosphate buffer, Mobile phase, Standard preparation, System suitability solution, and Chromatographic system—
Proceed as directed in the
Assay under
Dobutamine Hydrochloride.
Assay preparation—
Transfer an amount of Dobutamine in Dextrose Injection, equivalent to about 44.6 mg of dobutamine, accurately weighed, to a 100-mL volumetric flask, dilute with water to volume, and mix. [NOTE—Refrigerate until injected, and use within 8 hours.]
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 dobutamine (C
18H
23NO
3) in the portion of Dobutamine in Dextrose Injection taken by the formula:
(301.39/337.84)100C(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; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
