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Metronidazole Injection
» Metronidazole Injection is a sterile, isotonic, buffered solution of Metronidazole in Water for Injection. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of metronidazole (C6H9N3O3).
Packaging and storage
Preserve in single-dose containers of Type I or Type II glass, or in suitable plastic containers, protected from light.
Identification
A:
Apply a measured volume of Injection containing 0.025 mg of metronidazole and a measured volume of a solution of USP Metronidazole RS containing 0.025 mg of metronidazole to a suitable thin-layer chromatographic plate (see Chromatography
B:
The retention time of the major peak obtained from the Assay preparation corresponds to that of the Standard preparation obtained as directed in the Assay.
Bacterial endotoxins
pH
Particulate matter
Other requirements
It meets the requirements under Injections
Assay
Mobile phase
Prepare a suitable filtered and degassed mixture of monobasic potassium phosphate, prepared by dissolving 0.68 g of monobasic potassium phosphate in 930 mL of water, and methanol (930:70), and adjust with 1 M phosphoric acid to a pH of 4.0 ± 0.5.
Standard preparation
Transfer about 25 mg of USP Metronidazole RS, accurately weighed, to a 25-mL volumetric flask, dissolve in methanol, dilute with methanol to volume, and mix. Pipet 2 mL of this solution into a 10-mL volumetric flask containing 2 mL of water, dilute with Mobile phase to volume, and mix.
Assay preparation
Transfer an accurately measured volume of Injection, equivalent to about 25 mg of metronidazole, to a 25-mL volumetric flask, dilute with water to volume, and mix. Pipet 2 mL of this solution into a 10-mL volumetric flask containing 2 mL of methanol, dilute with Mobile phase to volume, and mix.
Chromatographic system
(see Chromatography
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 metronidazole (C6H9N3O3) in each mL of the Injection taken by the formula:
125C / V(rU / rS)
in which C is the concentration, in mg per mL, of USP Metronidazole RS in the Standard preparation; V is the volume, in mL, of Injection taken; and rU and rS are the peak responses for metronidazole obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3908
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