Zidovudine Injection
» Zidovudine Injection is a sterile solution of Zidovudine in Water for Injection. It contains not less than 90.0 percent and not more than 110.0 percent of zidovudine (C10H13N5O4).
Packaging and storage— Preserve in tight, light-resistant containers.
USP Reference standards 11
USP Endotoxin RS
USP Zidovudine RS Click to View Structure
USP Zidovudine Related Compound C RS Click to View Structure
Thymine.
    C5H6N2O2    126.12
Identification—
A: Ultraviolet Absorption 197U
Medium: methanol and water (75:25).
Solution: 15 µg per mL. Obtain the test solution as follows. Mix a volume of Injection, equivalent to 20 mg of zidovudine, with 50 mL of Medium in a 200-mL volumetric flask, and dilute with Medium to volume. Dilute the resulting solution 15 in 100 with Medium, and mix.
B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, as obtained in the Assay.
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 3.5 and 7.0, in a mixture containing a volume of Injection equivalent to 150 mg of zidovudine and 5 mL of 0.12 M potassium chloride.
Bacterial endotoxins 85 It contains not more than 1.0 USP Endotoxin Unit per mg of zidovudine.
Related compounds—
Mobile phase, Standard stock solution, Zidovudine related compound C standard stock solution, and Chromatographic system— Proceed as directed in the Assay.
Standard solution— Transfer 10.0 mL of Standard stock solution and 1.0 mL of Zidovudine related compound C standard stock solution to a 100-mL volumetric flask, add 25 mL of water, mix, dilute with methanol to volume, and mix.
Test solution— Proceed as directed for Assay preparation in the Assay.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the quantity, in mg, of zidovudine related compound C (thymine) in the volume of Injection taken by the formula:
1000C [(rU / rS) / Q]
in which C is the concentration, in mg per mL, of USP Zidovudine Related Compound C RS in the Standard solution; rU and rS are the peak responses of zidovudine related compound C (thymine) obtained from the Test solution and the Standard solution, respectively; and Q is the quantity, in mg, of zidovudine in the volume of Injection taken, as determined in the Assay: not more than 1.0% is found.
Other requirements— It meets the requirements under Injections 1.
Assay—
Mobile phase— Prepare a filtered and degassed mixture of water and methanol (80:20). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard stock solution— Dissolve an accurately weighed quantity of USP Zidovudine RS in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution having a known concentration of about 1.0 mg per mL.
Zidovudine related compound C standard stock solution— Transfer about 20 mg of USP Zidovudine Related Compound C RS, accurately weighed, to a 100-mL volumetric flask, add 75 mL of methanol, sonicate for 15 minutes, dilute with methanol to volume, and mix.
Standard preparation— Transfer 10.0 mL of Standard stock solution and 2.0 mL of Zidovudine related compound C standard stock solution to a 100-mL volumetric flask, add 25 mL of water, mix, dilute with methanol to volume, and mix.
Assay preparation— Transfer an accurately measured volume of Injection, equivalent to about 25 mg of zidovudine, to a 250-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 265-nm detector and a 4.0-mm × 25-cm column that contains packing L1 and a guard column with the recommended dimensions of 3.2-mm × 1.5-cm containing packing L1. The flow rate is about 1.0 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative retention times are about 0.2 for zidovudine related compound C (thymine) and 1.0 for zidovudine; the resolution, R, between zidovudine and zidovudine related compound C (thymine) is not less than 5.0; the tailing factor is not more than 1.5; and the relative standard deviation for replicate injections is not more 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. Calculate the quantity, in mg, of zidovudine (C10H13N5O4) in the volume of Injection taken by the formula:
1000C(rU / rS)
in which C is the concentration, in mg per mL, of USP Zidovudine RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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