Rocuronium Bromide
(roe'' kure oh' nee um broe' mide).
Click to View Image

C32H53BrN2O4
609.68
Pyrrolidinium, 1-[(2,3,5,16,17)-17-(acetyloxy)-3-hydroxy-2-(4-morpholinyl)androstan-16-yl]-1-(2-propenyl)-, bromide;    

1-Allyl-1-(3,17-dihydroxy-2-morpholino-5-androstan-16-yl)pyrrolidinium bromide, 17-acetate    
[119302-91-9].
DEFINITION
Rocuronium Bromide contains NLT 98.0% and NMT 102.0% of rocuronium bromide (C32H53BrN2O4), calculated on the anhydrous and 2-propanol-free or acetic acid-free basis.
IDENTIFICATION
•  B. The retention time of the rocuronium bromide peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
•  C. Identification Tests—General, Bromide 191
Sample solution:  10 mg/mL
Acceptance criteria:  Meets the requirements of the silver nitrate test
ASSAY
•  Procedure
Diluent:  Acetonitrile and water (90:10)
Buffer:  4.53 g/L of tetramethylammonium hydroxide pentahydrate. Adjust the solution with phosphoric acid to a pH of 7.4.
Mobile phase:  Acetonitrile and Buffer (90:10)
Standard solution:  1 mg/mL of USP Rocuronium Bromide RS in Diluent
Sample solution:  1 mg/mL of Rocuronium Bromide in Diluent
Chromatographic system 
Mode:  LC
Detector:  UV 210 nm
Column:  4.6-mm × 25-cm; 5-µm packing L3
Column temperature:  30
Flow rate:  2 mL/min
Injection volume:  5 µL
System suitability 
[Note—The system may need equilibration for 4 h. ]
Sample:  Standard solution
Suitability requirements 
Tailing factor:  NMT 2.0
Relative standard deviation:  NMT 2.0%
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of rocuronium bromide (C32H53BrN2O4) in the portion of the sample taken:
Result = (rU/rS) × (CS/CU) × 100

rU== peak response from the Sample solution
rS== peak response from the Standard solution
CS== concentration of USP Rocuronium Bromide RS in the Standard solution (mg/mL)
CU== concentration of Rocuronium Bromide in the Sample solution (mg/mL)
Acceptance criteria:  98.0%–102.0% on the anhydrous and 2-propanol-free or acetic acid-free basis
IMPURITIES
Delete the following:
•  Heavy Metals, Method II 231: NMT 10 ppm(Official 1-Dec-2015)
•  Residue on Ignition 281: NMT 0.1%
•  Organic Impurities
Diluent, Mobile phase, and Chromatographic system:  Proceed as directed in the Assay.
Peak identification solution:  1 mg/mL of USP Rocuronium Peak Identification Mixture RS in Diluent
Standard solution:  0.01 mg/mL of USP Rocuronium Bromide RS in Diluent
Sample solution:  10 mg/mL of Rocuronium Bromide in Diluent
Run time:  2.5 times the retention time for rocuronium
System suitability 
[Note—The system may need equilibration for 4 h. ]
Sample:  Peak identification solution
Suitability requirements 
Peak-to-valley ratio:  The ratio of the height of the rocuronium related compound H peak to the height of the valley between the rocuronium related compound H peak and the rocuronium peak is NLT 1.5.
Resolution:  NLT 3.5 between rocuronium and rocuronium related compound C
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of each impurity in the portion of Rocuronium Bromide taken:
Result = (rU/rS) × (CS/CU) × (1/F) × 100

rU== peak response of any impurity from the Sample solution
rS== peak response of rocuronium bromide from the Standard solution
CS== concentration of USP Rocuronium Bromide RS in the Standard solution (mg/mL)
CU== concentration of Rocuronium Bromide in the Sample solution (mg/mL)
F== relative response factor (see Table 1)
Acceptance criteria:  See Table 1.
[Note—Disregard any peak eluting before rocuronium bromide related compound A, and any peak with an area less than 0.5 times that of the principal peak from the Standard solution. ]
Table 1
Name Relative
Retention
Time
Relative
Response
Factor
Acceptance
Criteria,
NMT (%)
Rocuronium related compound Aa 0.20 2.1 0.2
Rocuronium related compound Gb 0.44 2.3 0.1
Rocuronium related compound Fc 0.75 0.79 0.1
Rocuronium related compound Bd 0.80 1.0 0.3
Rocuronium related compound De 0.90 1.0 0.1
Rocuronium related compound Hf 0.95 2.9 0.1
Rocuronium bromide 1.0
Rocuronium related compound Cg 1.20 1.0 0.3
Rocuronium related compound Eh 1.53 1.0 0.1
Any individual
unspecified impurity
0.10
Total impurities 1.5
a  3-Hydroxy-2-(morpholin-4-yl)-16-(pyrrolidin-1-yl)-5-androstan-17-yl acetate.
b  2-(Morpholin-4-yl)-16-(pyrrolidin-1-yl)-5-androstan-3,17-diol.
c  1-[3,17-Bis(acetyloxy)-2-(pyrrolidin-1-yl)-5-androstan-16-yl]-1-(prop-2-enyl)pyrrolidinium.
d  1-[3,17-Bis(acetyloxy)-2-(morpholin-4-yl)-5-androstan-16-yl]-1-(prop-2-enyl)pyrrolidinium.
e  1-[3-(Acetyloxy)-17-hydroxy-2-(morpholin-4-yl)-5-androstan-16-yl]-1-(prop-2-enyl)pyrrolidinium.
f  1-[17-(Acetyloxy)-2-(morpholin-4-yl)-3-oxo-5-androst-1-en-16-yl]-1-(prop-2-enyl)pyrrolidinium.
g  1-[3,17-Dihydroxy-2-(morpholin-4-yl)-5-androstan-16-yl]-1-(prop-2-enyl)pyrrolidinium.
h  1-[17-(Acetyloxy)-3-hydroxy-2-(pyrrolidin-1-yl)-5-androstan-16-yl]-1-(prop-2-enyl)pyrrolidinium.
•  Limit of 2-Propanol
[Note—Perform this test only if 2-propanol is a known organic manufacturing process impurity. ]
Standard stock solution:  Transfer 35.0 µL of ethyl ether, 32.0 µL of 2-propanol, and 19.0 µL of methylene chloride to a 100-mL volumetric flask containing 90 mL of dimethylformamide (DMF), and dilute with DMF to volume.
Standard solution:  Transfer 2.5 mL of the Standard stock solution to a 25-mL volumetric flask containing 20 mL of DMF, and dilute with DMF to volume.
Dilute standard solution:  Transfer 1.0 mL of the Standard solution and 4.0 mL of water to a 20-mL headspace vial. Immediately close the vial with a cap, and mix.
Sample solution:  Transfer 50 mg of Rocuronium Bromide to a 20-mL headspace vial. Dissolve in 1.0 mL of DMF. Add 4 mL of water, immediately close the vial with a cap, and mix.
Chromatographic system 
Mode:  GC
Detector:  Flame ionization
Column:  0.32-mm × 60-m fused silica; coated with a 1.8-µm layer of liquid phase G43
Temperatures 
Injector:  140
Detector:  280
Column:  See Table 2.
Table 2
Initial
Temperature
()
Temperature
Ramp
(/min)
Final
Temperature
()
Hold Time
at Final
Temperature
(min)
50 0 50 8
50 20 250 8
Carrier gas:  Helium with a linear velocity of 55 cm/s or nitrogen with a linear velocity of 25 cm/s
Injection type:  Split ratio, 1:6
Head space autosampler 
Sample equilibration temperature:  90
Sample equilibration time:  15 min
Transfer line temperature:  140
System suitability 
Sample:  Dilute standard solution
[Note—The relative retention times for ethyl ether, 2-propanol, and methylene chloride are 0.87, 1.0, and 1.08, respectively. ]
Suitability requirements 
Resolution:  NLT 1.0 between ethyl ether and 2-propanol; NLT 1.0 between 2-propanol and methylene chloride
Relative standard deviation:  NMT 10.0% for the 2-propanol peak
Analysis 
Samples:  Dilute standard solution and Sample solution
Calculate the percentage of 2-propanol in the portion of Rocuronium Bromide taken:
Result = [(rU/rS) × (V × D/W) × 100]/F

rU== peak response of any impurity from the Sample solution
rS== peak response of rocuronium bromide from the Dilute standard solution
V== volume of 2-propanol taken to prepare the Standard stock solution (µL)
D== relative density of 2-propanol, 0.786 mg/µL
W== weight of Rocuronium Bromide taken to prepare the Sample solution (mg)
F== dilution factor for the Standard solution, 1000
Acceptance criteria:  NMT 1.0%
•  Limit of Acetic Acid
[Note—Perform this test only if acetic acid is a known organic manufacturing process impurity. ]
Mobile phase:  6.1 g of sodium perchlorate in 800 mL of water. Adjust with 1 N sulfuric acid to a pH of 2.0. Dilute to 1 L.
Standard solution:  0.2 mg/mL of glacial acetic acid in Mobile phase
Sample solution:  6.0 mg/mL of Rocuronium Bromide in Mobile phase. [Note—Sonication may be necessary to completely dissolve the rocuronium bromide. ]
Chromatographic system 
Mode:  LC
Detector:  UV 205 nm
Column:  4.6-mm × 15-cm; packing L1
Column temperature:  30
Flow rate:  1 mL/min
Injection volume:  20 µL
System suitability 
Sample:  Standard solution
[Note—The retention time of acetic acid is about 3.8 min. ]
Suitability requirements 
Column efficiency:  NLT 5000 theoretical plates
Tailing factor:  NMT 1.8
Relative standard deviation:  NMT 5.0% for three injections
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of acetic acid in the portion of Rocuronium Bromide taken:
Result = (rU/rS) × (CS/CU) × 100

rU== peak response for acetic acid from the Sample solution
rS== peak response for acetic acid from the Standard solution
CS== concentration of acetic acid in the Standard solution (mg/mL)
CU== concentration of Rocuronium Bromide in the Sample solution (mg/mL)
Acceptance criteria:  NMT 5.0%
SPECIFIC TESTS
•  pH 791
Sample solution:  10 mg/mL
Acceptance criteria:  7.0–9.5
•  Optical Rotation, Specific Rotation 781S
Sample solution:  10 mg/mL in 0.05 M hydrochloric acid
Acceptance criteria:  28.5–32.0, measured on the anhydrous and solvent-free basis at 20
•  Color and Achromicity 631
Reference solution:  Mix 33 mL of Matching Fluid G and 67 mL of water.
Sample solution:  10 mg/mL of Rocuronium Bromide in water
Analysis:  Proceed as directed for Color and Achromicity 631.
Acceptance criteria:  The Sample solution is not more intensely colored than the Reference solution.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in tight containers, protected from light and moisture. Store in the freezer. If the article contains acetic acid, store it between 2 and 8.
•  USP Reference Standards 11
USP Rocuronium Bromide RS Click to View Structure
USP Rocuronium Peak Identification Mixture RS
Mixture of approximately 0.2% to 0.4% each of rocuronium related compound A, rocuronium related compound B, rocuronium related compound C, rocuronium related compound D, rocuronium related compound E, rocuronium related compound F, rocuronium related compound G, and rocuronium related compound H in a matrix of rocuronium bromide.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ravi Ravichandran, Ph.D.
Principal Scientific Liaison
(301) 816-8330
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP38–NF33 Page 5218
Pharmacopeial Forum: Volume No. 38(2)