Metoprolol Tartrate Injection
» Metoprolol Tartrate Injection is a sterile solution of Metoprolol Tartrate in Water for Injection. It contains Sodium Chloride as a tonicity-adjusting agent. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of metoprolol tartrate [(C15H25NO3)2·C4H6O6].
Packaging and storage Preserve in single-dose, light-resistant containers, preferably of Type I or Type II glass.
USP Reference standards 11
USP Endotoxin RS
Identification Place a volume of Injection, equivalent to about 40 mg of metoprolol tartrate, in a separator, add 4 mL of dilute ammonium hydroxide (1 in 3), and extract with 20 mL of chloroform, filtering the chloroform extract through chloroform-pre-rinsed anhydrous sodium sulfate. Evaporate the chloroform to dryness, and place in a freezer to congeal the residue: the IR absorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Metoprolol Tartrate RS.
Bacterial endotoxins 85 It contains not more than 25.0 USP Endotoxin Units per mg of metoprolol tartrate.
Sterility 71 It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined.
pH 791: between 5.0 and 8.0.
Other requirements It meets the requirements under Injections 1.
Mobile phase Prepare a degassed solution by dissolving 961 mg of 1-pentanesulfonic acid sodium salt (monohydrate) and 82 mg of anhydrous sodium acetate in a mixture of 550 mL of methanol and 470 mL of water and adding 0.57 mL of glacial acetic acid.
Internal standard solution Dissolve USP Oxprenolol Hydrochloride RS in freshly prepared Mobile phase to obtain a solution containing about 720 µg per mL.
Sodium chloride solution Dissolve 9.0 g of sodium chloride in water to make 1000 mL.
Standard preparation Dissolve an accurately weighed quantity of USP Metoprolol Tartrate RS in Sodium chloride solution to obtain a stock solution having a known concentration of about 1000 µg per mL. Mix equal volumes, accurately measured, of this stock solution and of Internal standard solution.
Assay preparation Dilute an accurately measured volume of Injection, if necessary, quantitatively with Sodium chloride solution to obtain a stock solution having a concentration of about 1000 µg per mL. Mix equal volumes, accurately measured, of this stock solution and of Internal standard solution.
Chromatographic system (see Chromatography 621)The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 1 mL per minute. Chromatograph three replicate injections of the Standard preparation, and record the peak responses as directed under Procedure: the relative standard deviation is not more than 2.0%, and the resolution factor between metoprolol tartrate and oxprenolol hydrochloride is not less than 2.0.
Procedure Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. The relative retention times are about 0.8 for metoprolol tartrate and 1.0 for oxprenolol hydrochloride. Calculate the quantity, in mg, of metoprolol tartrate [(C15H25NO3)2·C4H6O6] in each mL of the Injection taken by the formula:
(L / D)(C)(RU / RS)in which L is the labeled quantity, in mg, of metoprolol tartrate in the Injection; D is the concentration, in µg per mL, of metoprolol tartrate in the Assay preparation, on the basis of the labeled quantity in each mL of Injection taken and the extent of dilution; C is the concentration, in µg per mL, of USP Metoprolol Tartrate RS in the Standard preparation; and RU and RS are the peak response ratios of metoprolol tartrate to oxprenolol hydrochloride obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 3900