Etoposide Phosphate

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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Furo[3’,4’:6,7]naphtho[2,3-d]-1,3-dioxol-6(5aH)-one, 5-[3,5-dimethoxy-4-(phosphonooxy)phenyl]-9-[(4,6-O-ethylidene-β-d-

glucopyranosyl)oxy]-5,8,8a,9-tetrahydro-, [5R-[5α,5aβ,8aα,9β(R*)]]-;

4’-Demethylepipodophyllotoxin 9-[4,6-O-(R)-ethylidene-β-d-glucopyranoside], 4’-(dihydrogen phosphate);

(5R,5aR,8aR,9S)-9-[4,6-O-(R)-Ethylidene-β-d-glucopyranosyloxy]-5,8,8a,9-tetrahydro-5-[3,5-dimethoxy-4-

(phosphonooxy)phenyl]furo[3’,4’:6,7]naphtho[2,3-d]-1,3-dioxol-6(5aH)-one CAS RN^®: 117091-64-2; UNII: 528XYJ8L1N.

1 DEFINITION

Etoposide Phosphate contains NLT 97.5% and NMT 102:0% of etoposide phosphate (C₂₉H₃₃O₁₆P), calculated on the anhydrous and solvent-free basis.

[CAUTION-Etoposide phosphate is potentially cytotoxic. Great care should be taken to prevent inhaling particles and exposing the skin to it]

2 IDENTIFICATION

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197K or 197A

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

Solution A: 2.3 g/L of ammonium phosphate, monobasic in water

Mobile phase: Acetonitrile and Solution A (15:85). Adjust with phosphoric acid to a pH of 2.5.

Standard solution: 0.24 mg/mL of USP Etoposide Phosphate RS in Mobile phase. Sonicate to assist with dissolution.

Sample solution: 0.24 mg/ml of Etoposide Phosphate in Mobile phase. Sonicate to assist with dissolution.

Chromatographic system

(See Chromatography (621) System Suitability)

Mode: LC

Detector: UV 230 nm

Column: 4.6-mm × 15-cm; 5-μm packing L11

Flow rate: 1.5 mL/min

Injection volume: 25 μL

System suitability

Sample: Standard salution

Suitability requirements

Tailing factor: NMT 1.6

Relative standard deviation: NMT 0.73%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of etoposide phosphate (C₂₉H₃₃O₁₆P) in the portion of Etoposide Phosphate taken:

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

r_U = peak response of etoposide phosphate from the Sample solution

r_S = peak response of etoposide phosphate from the Standard solution

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

C_U = concentration of Etoposide Phosphate in the Sample solution (mg/mL)

Acceptance criteria: 97.5%-102.05 on the anhydrous and solvent free basis

4 IMPURITIES

Mobile phase, Sample solution, and Chromatographic system: Proceed as directed in the Assay.

Standard stock solution A: Use the Standard solution in the Assay.

Standard solution A: 0.24 μg/mL of USP Etoposide Phosphate RS in Mobile phase, from Standard stock solution A

Standard stock solution B: 0.024 mg/mL of USP Etoposide RS in acetonitrile

Standard solution B: 1.2 μg/mL of USP Etoposide RS in Mobile phase

Sensitivity solution: 0.12 μg/mL of USP Etoposide Phosphate RS in Mobile phase, from Standard solution A

System suitability

Samples: Standard solution A Standard solution 8, and Sensitivity solution

Suitability requirements

Relative standard deviation: NMT 10% for etoposide phosphate and etoposide, Standard solution A and Standard onion

Signal-to-noise ratio: NLT 10, Sitivity solution

Analysis

Samples: Sample solution, Standard solution A, and Standard solution

Calculate the percentage of etoposide and lignan P in the portion of Etoposide Phosphate taken:

Result = (r_U/(r_S) × (C_S /C_U) ) × (1/F) x 100

r_U = peak area of etoposide or lignan P from the Sample solution

r_S = peak area of etoposide from Standard solution B

C_S = concentration of USP Etoposide RS in Standard solution B (mg/mL)

C_U = concentration of Etoposide Phosphate in the Sample solution (mg/mL)

F = relative response factor (see Table 1)

Calculate the percentage of lignan P phosphate and any individual unspecified impurity in the portion of Etoposide Phosphate taken:

Result = (r_U/(r_S) × (C_S /C_U) ) × (1/F) x 100

r_U = peak area of lignan P phosphate and any individual unspecified impurity from the Sample solution

r_S = peak area of etoposide phosphate from Standard solution A

C_S = concentration of USP Etoposide Phosphate RS in Standard solution A (mg/mL)

C_U = concentration of Etoposide Phosphate in the Sample solution (mg/mL)

F = relative response factor (see Table 1)

Acceptance criteria: See Table 1. The reporting threshold is 0.05%

^a (5R,5aR,8aR,9S)-9-[β-d-Glucopyranosyloxy]-5,8,8a,9-tetrahydro-5-[3,5-dimethoxy-4-(phosphonooxy)phenyl]furo[3’,4’:6,7]naphtho[2,3-d]-1,3-dioxol-6(5aH)-one.

^b (5R,5aR,8aR,9S)-9-[β-d-Glucopyranosyloxy]-5,8,8a,9-tetrahydro-5-(4-hydroxy-3,5-dimethoxyphenyl)furo[3’,4’:6,7]naphtho[2,3-d]-1,3-dioxol-6(5aH)-one.

5 SPECIFIC TESTS

Optical Rotation (781S), Procedures, Specific Rotation

Sample solution: 10 mg/mL in water

Acceptance criteria: –77° to –81° at 20°

Water Determination (921), Method I: NMT 0.5%

Bacterial Endotoxins Test (85): Where the label states that Etoposide Phosphate must be subjected to further processing during the preparation of injectable dosage forms, the level of bacterial endotoxins are such that the requirement under the relevant dosage form monograph(s) in which Etoposide Phosphate is used can be met.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers. Store at room temperature.

Labeling: Where Etoposide Phosphate must be subjected to further processing during the preparation of injectable dosage forms to ensure acceptable levels of bacterial endotoxins, it is so labeled.