Trenbolone Acetate
(tren' boe lone as' e tate).
Click to View Image

C20H24O3 312.40
Estra-4,9,11-trien-3-one, 17-(acetyloxy)-, (17)-;    
17-Hydroxyestra-4,9,11-trien-3-one, acetate     [10161-34-9].
DEFINITION
Trenbolone Acetate contains NLT 97.0% and NMT 103.0% of C20H24O3, calculated on the dried basis.
IDENTIFICATION
•  B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
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.
Time
(min)
Solution A
(%)
Solution B
(%)
0 100 0
6 100 0
16 0 100
26 0 100
26.1 100 0
30 100 0
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  
Mode:  LC
Detector:  UV 229 nm
Column:  4.6-mm × 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 = (rU/rS) × (CS/CU) × 100
rU== peak response of Trenbolone Acetate from the Sample solution
rS== peak response of trenbolone acetate from the Standard solution
CS== concentration of USP Trenbolone Acetate RS in the Standard solution (mg/mL)
CU== concentration of Trenbolone Acetate in the Sample solution (mg/mL)
Acceptance criteria:  97.0%–103.0%, on the dried basis
IMPURITIES
Inorganic Impurities 
•  Residue on Ignition 281: NMT 0.1%
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 trenbolone acetate related compound A and trenbolone acetate are 1.2 and 1.0, respectively. ]
Suitability requirements 
Resolution:   NLT 3.0 between trenbolone acetate and trenbolone acetate related compound A, 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 × rU)/[(rS + S) × F]
rU== peak response of each impurity from the Sample solution
rS== 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
Name Relative
Retention
Time
Relative
Response
Factor
Acceptance
Criteria,
NMT (%)
Trenbolone related compound Ba 0.4 1.04 1.0
Trenbolone related compound Cb 0.8 1.10 0.5
Trenbolone acetate 1.0
Related compound Ac 1.2 1.0 0.5
Any unspecified impurity 1.00d 0.5
a  Trenbolone.
b  Trenbolone acetate 17-isomer.
c  Conjugated dihydrotrenbolone acetate, or 11,12-dihydrotrenbolone acetate.
d  Unless determined otherwise.
SPECIFIC TESTS
•  Absorbance
Sample solution:  100 mg/mL in dehydrated alcohol
Spectrometric conditions 
Analytical wavelength:  440 nm
Cell:  2 cm
Blank:  Dehydrated alcohol
Analysis 
Samples:  Sample solution and Blank
Acceptance criteria:  NMT 0.3
•  Optical Rotation, Specific Rotation 781S: +39 to +43
Sample solution:  5 mg/mL in methanol
•  Loss on Drying 731: Dry a sample in a vacuum at 60 for 2 h: it loses NMT 0.5% of its weight.
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.
•  USP Reference Standards 11
USP Trenbolone Acetate RS
USP Trenbolone Acetate System Suitability Mixture RS
Mixture containing trenbolone and conjugated dihydrotrenbolone acetate in a matrix of trenbolone acetate.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Morgan Puderbaugh, B.S.
Associate Scientific Liaison
1-301-998-6833
(SM32010) Monographs - Small Molecules 3
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 4919
Pharmacopeial Forum: Volume No. 35(1) Page 100