Ethanol, 1-(4-amino-3,5-dichlorophenyl)-2-(tert-butylamino), hydrochloride;
4-Amino--[(tert-butylamino)methyl]-3,5-dichlorobenzyl alcohol, hydrochloride [21898-19-1].
Clenbuterol Hydrochloride contains NLT 98.0% and NMT 102.0% of C12H18Cl2N2O·HCl, calculated on the anhydrous basis.
• B. Identification TestsGeneral, Chloride 191: Meets the requirements
Sample solution: Dissolve 0.25 g in 50 mL of alcohol, and add 5.0 mL of 0.01 N hydrochloric acid.
Analysis: Titrate with 0.1 N sodium hydroxide VS, determining the endpoint potentiometrically. Read the volume added between the two points of inflection. Perform a blank determination, and make any necessary correction (see Titrimetry 541). Each mL of 0.1 N sodium hydroxide is equivalent to 31.37 mg of C12H18Cl2N2O·HCl.
Acceptance criteria: 98.0%102.0% on the anhydrous basis
• Residue on Ignition 281: NMT 0.1%, from 12 g
• Heavy Metals, Method II 231: NMT 10 ppm
Buffer: Dissolve 3.0 g of sodium 1-decanesulfonate and 5.0 g of monobasic potassium phosphate in 900 mL of water, adjust with dilute phosphoric acid (1 in 10) to a pH of 3.0, and dilute with water to 1000 mL.
Mobile phase: Acetonitrile, methanol, and Buffer (2:2:6)
System suitability solution: 0.2 mg/mL each of USP Clenbuterol Related Compound B RS and Clenbuterol Hydrochloride in Mobile phase
Sample solution 1: 2.0 mg/mL of Clenbuterol Hydrochloride in Mobile phase
Sample solution 2: 2.0 µg/mL of Clenbuterol Hydrochloride in Mobile phase, from Sample solution 1
Detector: UV 215 nm
Column: 4.0-mm × 12.5-cm; 5-µm packing L1
Column temperature: 40
Flow rate: 0.5 mL/min
Injection size: 5 µL
Sample: System suitability solution
Resolution: NLT 4.0 between clenbuterol related compound B and clenbuterol
Relative standard deviation: NMT 2.0% for the clenbuterol peak
Samples: Sample solution 1 and Sample solution 2
Calculate the percentage of impurities in the portion of C12H18Cl2N2O·HCl taken:
Result = (rU/rS) × (CS/CU) × 100
Individual impurities: 0.1%
Total impurities: NMT 0.2%
[NoteThe reporting level for impurities is 0.05%. ]
• Optical Rotation, Specific Rotation 781S
Sample: 30 mg/mL in water, filter as necessary
Acceptance criteria: 10 to +10 at 20
• pH 791: 5.07.0
Sample: 50 mg/mL in carbon dioxide-free water
• Water Determination, Method I 921: NMT 1.0%
• Packaging and Storage: Preserve in well-closed containers, protected from light. Store at room temperature.
• Labeling: Label it to indicate that it is for veterinary use only.
• USP Reference Standards 11
USP Clenbuterol Related Compound B RS
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 2700Pharmacopeial Forum: Volume No. 35(5) Page 1125