Zidovudine Capsules

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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1 DEFINITION

Zidovudine Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of zidovudine (C₁₀H₁₃N₅O₄).

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U (CN 1-May-2020)

Solution A: Methanol and water (75:25)

Sample solution: 15 µg/mL prepared as follows. Mix Capsule contents, equivalent to 300 mg of zidovudine, with 50 mL of Solution A in a 200- mL volumetric flask. Sonicate for 5 min, and dilute with methanol to volume. Allow insoluble solids to settle, and dilute the supernatant 100- fold with Solution A.

Acceptance criteria: Meet the requirements

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

Procedure

Mobile phase: Methanol and water (20:80)

Diluent: Methanol and water (75:25)

Standard stock solution: 1.0 mg/mL of USP Zidovudine RS in methanol

Zidovudine related compound C standard stock solution: 0.2 mg/mL of USP Zidovudine Related Compound C RS in methanol prepared as follows. Transfer 20 mg of USP Zidovudine Related Compound C RS to a 100-mL volumetric ask, add 75 mL of methanol, sonicate for 15 min, dilute with methanol to volume.

Standard solution: 0.1 mg/mL of USP Zidovudine RS and 2 µg/mL of USP Zidovudine Related Compound C RS prepared as follows. Transfer 10 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, and dilute with methanol to volume.

Sample stock solution: Nominally 1 mg/mL of zidovudine in Diluent prepared as follows. Weigh the contents of Capsules (NLT 20), mix, and transfer a portion of the powder, equivalent to 100 mg of zidovudine, to a 100-mL volumetric flask. Dissolve in Diluent, sonicate for 20 min, and dilute with Diluent to volume. Allow the solids to settle, and use the supernatant layer to prepare the Sample solution.

Sample solution: Nominally 0.1 mg/mL of zidovudine from a suitable volume of supernatant of Sample stock solution in Diluent. Filter, discarding the first 4 mL of the filtrate.

3.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 265 nm

Columns

Guard: Recommended dimensions are 3.2-mm × 1.5-cm; packing L1.

Analytical: 4.0-mm × 25-cm; packing L1

Flow rate: 1 mL/min

Injection volume: 10 µL

3.2 System suitability

Sample: Standard solution

[Note—The relative retention times for zidovudine related compound C and zidovudine are about 0.2 and 1.0, respectively.] Suitability requirements

Resolution: NLT 5.0 between the zidovudine and zidovudine related compound C peaks

Tailing factor: NMT 2.0 for the zidovudine peak

Relative standard deviation: NMT 2.0% for the zidovudine peak

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of zidovudine (C₁₀H₁₃N₅O₄) in the portion of Capsules taken:

Result = (r_U /r_S ) × (C_S /C_U ) × 100

r_U = peak response of zidovudine from the Sample solution

r_S = peak response of zidovudine from the Standard solution

C_S = concentration of USP Zidovudine RS in the Standard solution (mg/mL)

C_U = nominal concentration of the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 50 rpm

Time: 45 min

Mobile phase, Chromatographic system, and System suitability: Proceed as directed in the Assay. Standard solution: Prepare a solution having a known concentration of USP Zidovudine RS in Medium. Sample solution: A filtered portion of the solution under test, suitably diluted with Medium

Analysis

Samples: Standard solution and Sample solution

Determine the percentage of zidovudine (C₁₀H₁₃N₅O₄) dissolved by using the procedure set forth in the Assay, making any necessary modifications.

Tolerances: NLT 75% (Q) of the labeled amount of zidovudine (C₁₀H₁₃N₅O₄) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 IMPURITIES

Organic Impurities

Mobile phase, Diluent, Zidovudine related compound C standard stock solution, Standard stock solution, Standard solution, Sample stock solution, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of zidovudine related compound C in the portion of Capsules taken:

Result = (r_U /r_S ) × (C_S /C_U ) × 100

r_U = peak response of zidovudine related compound C from the Sample solution

r_S = peak response of zidovudine related compound C from the Standard solution

C_S = concentration of USP Zidovudine Related Compound C RS in the Standard solution (mg/mL)

C_U = nominal concentration of zidovudine in the Sample solution (mg/mL)

Acceptance criteria: NMT 3.0%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers.

USP Reference Standards 〈11〉

USP Zidovudine RS

USP Zidovudine Related Compound C RS

Thymine.

C₅H₆N₂O₂  126.12