Trenbolone 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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C₂₀H₂₄O₃         ^▲312.41_{▲(CN 1-Aug-2023)}

Estra-4,9,11-trien-3-one, 17-(acetyloxy)-, (17β)-;

^▲(17β)-3-Oxoestra-4,9,11-trien-17-yl acetate _{▲(CN 1-Aug-2023)}      CAS RN^®: 10161-34-9; UNII: RUD5Y4SV0S..

1 DEFINITION

Trenbolone Acetate contains NLT 97.0% and NMT 103.0% of C₂₀H₂₄O₃, calculated on the dried basis. 

2 IDENTIFICATION

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

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

Diluent: Acetonitrile, methanol, water, and acetic acid (36.5:30:33.5:0.1)

Solution A: Acetonitrile, methanol, and water (36.5:30:33.5)

Solution B: Acetonitrile and methanol (9:1)

Mobile phase: See the gradient table below.

Standard solution: 1 mg/mL of USP Trenbolone Acetate RS in Diluent. Sonicate, if necessary, to dissolve.

Sample solution: 1 mg/mL of Trenbolone Acetate in Diluent. Sonicate, if necessary, to dissolve.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 229 nm

Column: 4.6-mm x 10-cm; 3-µm packing L1

Flow rate: 1.0 mL/min

Injection size: 5 µL

System suitability

Samples: Standard solution

Suitability requirements

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of C₂₀H₂₄O₃, in the portion of Trenbolone Acetate taken: 

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

r_U = peak response of Trenbolone Acetate from the Sample solution Tu

r_S = peak response of trenbolone acetate from the Standard solution S

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

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

Acceptance criteria: 97.0%-103.0%, on the dried basis

4 IMPURITIES

4.1 INORGANIC IMPURITIES

RESIDUE ON IGNITION (281): NMT 0.1%

Change to read:

4.2 ORGANIC IMPURITIES

PROCEDURE

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

System suitability solution: 1 mg/mL of USP Trenbolone Acetate System Suitability Mixture RS in Diluent. Sonicate, if necessary, to dissolve.

System suitability

Samples: Standard solution and System suitability solution

[NOTE-The relative retention times for ^▲11,12-dihydrotrenbolone acetate _{▲(CN 1-Aug-2023)} and trenbolone acetate are 1.2 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 3.0 between trenbolone acetate and ^▲11,12-dihydrotrenbolone acetate _{▲(CN 1-Aug-2023)}, System suitability solution

Column efficiency: NLT 8000 theoretical plates for the trenbolone acetate peak, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Sample: Sample solution

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

Result = (100 x r_U)/[(r_S + S) × F]

r_U = peak response of each impurity from the Sample solution

r_S = peak response of Trenbolone Acetate from Sample solution.

S = sum of the peak responses of each impurity, each divided by their respective response factor

F = relative response factor (see Impurity Table 1)

Acceptance criteria

Individual impurities: See Impurity Table 1.

Total specified and unspecified impurities: NMT 2.0%

Reporting level for impurities: NMT 0.10%

Impurity Table 1

^a  17β-Hydroxyestra-4,9,11-trien-3-one.

^b (17α )-3-Oxoestra-4,9,11-trien-17-yl acetate.

^c (17β)-3-Oxoestra-4,9-dien-17-yl acetate

^d Unless determined otherwise.

5 SPECIFIC TESTS

5.1 ABSORBANCE

Sample solution: 100 mg/mL in dehydrated alcohol

Spectrometric conditions

(See Ultraviolet-Visible Spectroscopy (857).)

Analytical wavelength: 440 nm

Cell: 2 cm

Blank: Dehydrated alcohol

Analysis

Samples: Sample solution and Blank

Acceptance criteria: NMT 0.3

5.2 OPTICAL ROTATION, Specific Rotation (7815): +39° to + 43°

Sample solution: 5 mg/mL in methanol

5.3 LOSS ON DRYING (731)

Dry a sample in a vacuum at 60° for 2 h: it loses NMT 0.5% of its weight.

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers, and store in a refrigerator.

LABELING: Label it to indicate that it is for veterinary use only.

Change to read:

USP REFERENCE STANDARDS (11)

USP Trenbolone Acetate RS

USP Trenbolone Acetate System Suitability Mixture RS

Mixture containing trenbolone and ^▲11,12-dihydrotrenbolone acetate _{▲(CN 1-Aug-2023)} in a matrix of trenbolone acetate.