Zidovudine
(zye doe' vue deen).
+'&img=../../images/v35300/g-1415.gif&casNumber=30516-87-1&usp=35&nf=30&chemicalStructureImage=true&ID='+parent.myID,600,500);)
267.24Thymidine, 3¢-azido-3¢-deoxy-.
3¢-Azido-3¢-deoxythymidine
[30516-87-1].» Zidovudine contains not less than 97.0 percent and not more than 102.0 percent of C10H13N5O4, calculated on the anhydrous basis.
Packaging and storage—
Preserve in tight, light-resistant containers. Store at 25
, excursions permitted between 15 and 30.
, excursions permitted between 15 and 30.
USP Reference standards 
11
—
11—
USP Zidovudine RS 
') + '&img=../../images/v35300/cas-30516-87-1.gif',600,500);)
USP Zidovudine Related Compound B RS
3¢-Chloro-3¢-deoxythymidine.
C10H13ClN2O4 260.68
') + '&img=../../images/v35300/c11rs1266.gif',600,500);)
3¢-Chloro-3¢-deoxythymidine.
C10H13ClN2O4 260.68
USP Zidovudine Related Compound C RS
Thymine.
C5H6N2O2 126.12
') + '&img=../../images/v35300/c11rs1267.gif',600,500);)
Thymine.
C5H6N2O2 126.12
Identification—
B:
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.
Water, Method I 921:
not more than 1.0%.
921:
not more than 1.0%.
Residue on ignition 281:
not more than 0.25%.
281:
not more than 0.25%.
Chromatographic purity—
test a—
Standard solution—
Dissolve accurately weighed quantities of USP Zidovudine RS, and triphenylmethanol in methanol, and mix to obtain a solution having known concentrations of about 0.1 mg of each per mL.
Test solution—
Dissolve an accurately weighed quantity of Zidovudine in methanol to obtain a solution containing 20 mg per mL.
Procedure—
Separately apply 10 µL of the Test solution and 10 µL of the Standard solution to a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture containing a fluorescent indicator having an optimal intensity at 254 nm. Develop the chromatogram in a solvent system consisting of chloroform and methanol (9:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, mark the solvent front, and allow the solvent to evaporate. Examine the plate under short-wavelength UV light, and compare the intensities of any secondary spots observed in the chromatogram of the Test solution with those of the principal spot in the chromatogram of the Standard solution: no secondary spot from the chromatogram of the Test solution is larger or more intense than the principal spot obtained from the Standard solution, and the sum of the intensities of the secondary spots obtained from the Test solution corresponds to not more than 3.0%. Spray the plate with a mixture of 0.5 g of carbazole in 95 mL of alcohol and 5 mL of sulfuric acid, heat for 10 minutes at 120, and compare the intensities of any secondary spots observed in the chromatogram of the Test solution with those of the principal spots in the chromatogram of the Standard solution: no spot corresponding to triphenylmethanol (RF value about 2.3 relative to the RF value of zidovudine) is more intense than the corresponding spot from the Standard solution, no secondary spot from the chromatogram of the Test solution is larger or more intense than the principal spot obtained from the Standard solution, and the sum of the intensities of the secondary spots obtained from the Test solution corresponds to not more than 3.0%.
621) coated with a 0.25-mm layer of chromatographic silica gel mixture containing a fluorescent indicator having an optimal intensity at 254 nm. Develop the chromatogram in a solvent system consisting of chloroform and methanol (9:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, mark the solvent front, and allow the solvent to evaporate. Examine the plate under short-wavelength UV light, and compare the intensities of any secondary spots observed in the chromatogram of the Test solution with those of the principal spot in the chromatogram of the Standard solution: no secondary spot from the chromatogram of the Test solution is larger or more intense than the principal spot obtained from the Standard solution, and the sum of the intensities of the secondary spots obtained from the Test solution corresponds to not more than 3.0%. Spray the plate with a mixture of 0.5 g of carbazole in 95 mL of alcohol and 5 mL of sulfuric acid, heat for 10 minutes at 120, and compare the intensities of any secondary spots observed in the chromatogram of the Test solution with those of the principal spots in the chromatogram of the Standard solution: no spot corresponding to triphenylmethanol (RF value about 2.3 relative to the RF value of zidovudine) is more intense than the corresponding spot from the Standard solution, no secondary spot from the chromatogram of the Test solution is larger or more intense than the principal spot obtained from the Standard solution, and the sum of the intensities of the secondary spots obtained from the Test solution corresponds to not more than 3.0%.
test b—
Proceed as directed in the Assay, using the Assay preparation as the test solution. Calculate the percentage of each impurity in the portion of Zidovudine 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 zidovudine related compound B and not more than 2.0% of zidovudine related compound C are found, and the sum of all impurities from Test A and Test B is not more than 3.0%.
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).
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 B standard stock solution—
Dissolve an accurately weighed quantity of USP Zidovudine Related Compound B RS in methanol, and dilute quantitatively, and stepwise if necessary, with methanol to obtain a solution having a known concentration of about 0.1 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, 1.0 mL of Zidovudine related compound B standard stock solution, and 1.0 mL of Zidovudine related compound C standard stock solution to a 100-mL volumetric flask, dilute with methanol to volume, and mix.
Assay preparation—
Transfer about 100 mg of Zidovudine, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with methanol to volume, and mix. Transfer 10.0 mL of this solution to a 100-mL volumetric flask, dilute with methanol 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 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 0.25 for zidovudine related compound C (thymine), 1.0 for zidovudine, and 1.17 for zidovudine related compound B (3¢-chloro-3¢-deoxythymidine); the resolution, R, between zidovudine and zidovudine related compound B is not less than 1.4; the tailing factor is not more than 1.5; and the relative standard deviation for replicate injections is not more than 2.0%.
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 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 0.25 for zidovudine related compound C (thymine), 1.0 for zidovudine, and 1.17 for zidovudine related compound B (3¢-chloro-3¢-deoxythymidine); the resolution, R, between zidovudine and zidovudine related compound B is not less than 1.4; 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 C10H13N5O4 in the portion of Zidovudine 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.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Leonel M. Santos, Ph.D.
Senior Scientific Liaison 1-301-816-8168 |
(SM12010) Monographs - Small Molecules 1 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 5060
Pharmacopeial Forum: Volume No. 34(3) Page 656