Abiraterone Acetate

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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C₂₆H₃₃NO₂ 391.55

Androsta-5,16-dien-3-ol, 17-(3-pyridinyl)-, acetate (ester), (3β);

17-(Pyridin-3-yl)androsta-5,16-dien-3β-yl acetate CAS RN®: 154229-18-2; UNII: EM5OCB9YJ6.

1 DEFINITION

Abiraterone Acetate contains NLT 98.0% and NMT 102.0% of abiraterone acetate (C₂₆H₃₃NO₂), calculated on the as-is basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020)

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

3.1 Procedure

Solution A: 10 mM of ammonium acetate in water

Mobile phase: See Table 1.

Table 1:

[Note—Protect solutions from light.]

System suitability solution: 0.625 mg/mL of USP Abiraterone System Suitability Mixture RS in acetonitrile. [Note—See Table 2 for relative retention times of the main components of the mixture.]

Table 2

Standard solution: 0.625 mg/mL of USP Abiraterone Acetate RS in acetonitrile

Sample solution: 0.625 mg/mL of Abiraterone Acetate in acetonitrile

Chromatographic system

Mode: LC

Detector: UV 254 nm

Column: 3-mm × 15-cm; 3-μm packing L1

Column temperature: 15°

Flow rate: 0.45 mL/min

Injection volume: 10 μL

3.2 System suitability

Samples: System suitability solution and Standard solution

3.3 Suitability requirements

Resolution: NLT 1.0 between anhydro abiraterone and 3-deoxy 3-chloroabiraterone peaks, System suitability solution

Relative standard deviation: NMT 0.73%, Standard solution

3.4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of abiraterone acetate (C H NO ) in the portion of Abiraterone Acetate taken:

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

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

C_U = concentration of Abiraterone Acetate in the Sample solution (mg/mL)

Acceptance criteria: 98.0%–102.0% on the as-is basis

4 IMPURITIES

• Residue on Ignition 〈281〉: NMT 0.1%

• Organic Impurities

Solution A, Mobile phase, System suitability solution, Standard solution, Sample solution, and Chromatographic system: Proceed as directed in the Assay.

Sensitivity solution: 0.3 μg/mL of USP Abiraterone Acetate RS in acetonitrile, from Standard solution

4.1 System suitability

Samples: System suitability solution, Standard solution, and Sensitivity solution

4.2 Suitability requirements

Resolution: NLT 1.0 between anhydro abiraterone and 3-deoxy 3-chloroabiraterone peaks, System suitability solution

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

Relative standard deviation: NMT 0.73%, Standard solution

4.3 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each impurity in the portion of Abiraterone Acetate taken:

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

r_U = peak area of each impurity from the Sample solution

r_S = peak area of abiraterone acetate from the Standard solution

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

C_U = concentration of Abiraterone Acetate in the Sample solution (mg/mL)

F = relative response factor for each individual impurity (see Table 3)

Acceptance criteria: See Table 3. Disregard any peak less than 0.05%.

Table 3

5 SPECIFIC TESTS

• Water Determination, Method Ic〈921〉: NMT 0.25%

6 ADDITIONAL REQUIREMENTS

• Packaging and Storage: Preserve in well-closed containers. Store at controlled room temperature and protect from light.

• USP Reference Standards 〈11〉

USP Abiraterone Acetate RS

USP Abiraterone System Suitability Mixture RS

It contains Abiraterone Acetate and small amounts of the following:

Abiraterone

17-(Pyridin-3-yl)androsta-5,16-dien-3β-ol.

C₂₄H₃₁NO 349.52

Abiraterone ethyl ether

3β-Ethoxy-17-(pyridin-3-yl)androsta-5,16-diene.

C₂₆H₃₅NO 377.57

Abiraterone isopropyl ether

3β-Isopropoxy-17-(pyridin-3-yl)androsta-5,16-diene.

C₂₇H₃₇NO 391.60

Anhydro abiraterone

17-(Pyridin-3-yl)androsta-3,5,16-triene.

C₂₄H₂₉N 331.50

O-Chlorobutylabiraterone

3β-(4-Chlorobutoxy)-17-(pyridin-3-yl)androsta-5,16-diene.

C₂₈H₃₈ClNO 440.07

3-Deoxy-3-acetyl abiraterone-3-ene

1-[17-(Pyridin-3-yl)androsta-3,5,16-trien-3-yl]ethanone.

C₂₆H₃₁NO 373.53

3-Deoxy 3-chloroabiraterone

3β-Chloro-17-(pyridin-3-yl)androsta-5,16-diene.

C₂₄H₃₀ClN 367.96

α-Epoxyabiraterone acetate

17-(Pyridin-3-yl)-16α,17α-epoxyandrost-5-en-3β-yl acetate.

C₂₆H₃₃NO₃ 407.55

β-Epoxyabiraterone acetate

17-(Pyridin-3-yl)-16β,17β-epoxyandrost-5-en-3β-yl acetate.

C₂₆H₃₃NO₃ 407.55

7-Ketoabiraterone acetate

7-Oxo-17-(pyridin-3-yl)androsta-5,16-dien-3β-yl acetate.

C₂₆H₃₁NO₃ 405.54