Stavudine 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

Stavudine Capsules contain NLT 90.0% and NMT 105.0% of the labeled amount of stavudine.

2 IDENTIFICATION

Change to read:

A. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay. 2S (USP41)

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

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Procedure

All solutions containing stavudine must be prepared immediately before use and remain refrigerated until use.

Solution A: 0.77 g/L of ammonium acetate in water

Mobile phase: Acetonitrile and Solution A (5:95)

System suitability solution: 0.1 μg/mL each of USP Zidovudine Related Compound C RS 2S (USP41) and USP Zidovudine Related

Compound D RS2S (USP41) in water

Standard solution: 0.1 mg/mL of USP Stavudine RS in water. Use sonication to dissolve before dilution.

Sample solution: Nominally 0.1 mg/mL of stavudine prepared as follows. Open NLT 3 Capsules, and dissolve the contents in water. Dilute with water to obtain the final concentration.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 268 nm. For Identification A, use a diode array detector in the range of 190–400 nm. 2S (USP41)

Column: 4.6-mm × 3.3-cm; 3-μm 2S (USP41) packing L1

Flow rate: 0.7 mL/min

Injection volume: 20 μL

System suitability

Samples: System suitability solution and Standard solution

[Note—The retention time of the stavudine peak in the Standard solution is between 2.8 and 5.0 min.]

Suitability requirements

Resolution: NLT 2.0 between zidovudine related compound C2S (USP41) and zidovudine related compound D; zidovudine related compound C2S (USP41) is resolved from the void volume, System suitability solution 2S (USP41)

Tailing factor: NMT 1.8, Standard solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of stavudine (C₁₀H₁₂N₂O₄) in the portion of Capsules taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S= peak response from the Standard solution

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

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

Acceptance criteria: 90.0%–105.0%

4 PERFORMANCE TESTS

Change to read:

Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 75 rpm

Time: 30 min

Solution A and Mobile phase: Prepare as directed in the Assay.

Sample solution: Dilute with Medium to a concentration that is similar to the Standard solution. 2S (USP41)

Standard solution: USP Stavudine RS in Medium with a concentration corresponding to that of the Sample solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 3.3-cm; 3-μm 2S (USP41) packing L1

Flow rate: 0.7 mL/min

Injection volume: 10 μL

System suitability

Sample: Standard solution

Suitability requirements

2S (USP41)

Tailing factor: NMT 2

Relative standard deviation: NMT 2.0%

Analysis

Samples: Sample solution and Standard solution

Determine the percentage of the labeled amount of stavudine dissolved, using the procedure set forth in the Assay, making any necessary modi

cations.

Tolerances: NLT 80% (Q) of the labeled amount of stavudine is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 IMPURITIES

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Organic Impurities

Solution A, Mobile phase, System suitability solution, and Sample solution: Prepare as directed in the Assay.

Standard solution: 0.001 mg/mL of USP Zidovudine Related Compound C RS.2S (USP41) Use sonication to dissolve before dilution.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 268 nm

Column: 4.6-mm × 3.3-cm; 3-μm 2S (USP41) packing L1

Flow rate: 0.7 mL/min

Injection volume: 20 μL

Run time: NLT 2S (USP41) 2.5 times the retention time of the stavudine peak

System suitability

Samples: System suitability solution and Standard solution

[Note—The retention time of the stavudine peak in the Standard solution is between 2.8 and 5.0 min.]

Suitability requirements

Resolution: NLT 2.0 between zidovudine related compound C2S (USP41) and zidovudine related compound D; zidovudine related compound C2S (USP41) is resolved from the void volume, System suitability solution 2S (USP41)

Tailing factor: NMT 1.8, Standard solution

Relative standard deviation: NMT 3.0%, Standard solution

Analysis

Samples: Sample solution and Standard solution

Calculate the percentage of zidovudine related compound C 2S (USP41) in the portion of Capsules taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of zidovudine related compound C2S (USP41) from the Sample solution

r_S = peak response of zidovudine related compound C2S (USP41) from the Standard solution

C_S = concentration of USP Zidovudine Related Compound C RS2S (USP41) in the Standard solution (mg/mL)

C_U = nominal concentration of stavudine 2S (USP41) in the Sample solution (mg/mL)

Calculate the percentage of unknown impurities, not including zidovudine related compound C, 2S (USP41) in the portion of Capsules taken:

Result = (r_U/r_T) × 100

r_U = peak response of each impurity from the Sample solution

r_T = sum of all the peak responses from the Sample solution

Acceptance criteria: See Table 1. The disregard threshold is 0.05% of the total sample related peak response.

Table 1

^a 5-Methylpyrimidine-2,4-(1H,3H)-dione. 2S (USP41)

^b Includes zidovudine related compound C.2S (USP41)

6 SPECIFIC TESTS

Optical Rotation 〈781S〉, Procedures, Specific Rotation

Sample solution: Nominally 10 mg/mL of stavudine in water. Disperse a suficient quantity of Capsule contents, equivalent to 200 mg of stavudine, in 50 mL of acetone. Bring to a boil, and pass through a fine-porosity filter. Precipitate the stavudine with 150 mL of heptane, filter the crystals, wash with heptane, and dry in air.

Acceptance criteria: −40° to −45°

Water Determination 〈921〉, Method I: NMT 3.5%

7 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tightly closed containers, and store at controlled room temperature.

Change to read:

USP Reference Standards 〈11〉

USP Stavudine RS

USP Zidovudine Related Compound C RS