C
65H
82N
2O
18S
2
1243.48
Isoquinolinium, 2,2
¢-[1,5-pentanediylbis[oxy(3-oxo-3,1-propanediyl)]]bis[1-[(3,4-dimethoxyphenyl)methyl]-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-, dibenzenesulfonate.
2-(2-Carboxyethyl)-1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-veratrylisoquinolinium benzenesulfonate, pentamethylene ester
[
64228-81-5].
Packaging and storage
Preserve in tight, light-resistant containers, in a cold place. [NOTEAtracurium Besylate is unstable at room temperature.]
Identification
A:
Infrared Absorption 197K.
B:
The retention times of the three main isomeric peaks in the chromatogram of the Assay preparation correspond to those in the chromatogram of the Standard preparation, as obtained in the Assay.
Limit of methyl benzenesulfonate
Buffer solution, Solution A, Solution B, and Mobile phase
Prepare as directed in the Assay.
Standard solution
Prepare a solution of methyl benzenesulfonate in acetonitrile having a known concentration of about 0.2 mg per mL. Quantitatively dilute a portion of this solution with Solution A to obtain a solution having a known concentration of about 1 µg per mL.
Test solution
Transfer about 100 mg of Atracurium Besylate, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with Solution A to volume, and mix.
Resolution solution
Transfer 1 mL of the Test solution and 5 mL of a solution containing 0.2 mg of methyl benzenesulfonate per mL to a 100-mL volumetric flask, dilute with Solution A to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 217-nm detector and a 4.6-mm × 25-cm column that contains base-deactivated packing L1. The flow rate is about 1 mL per minute. The chromatograph is programmed as follows.
Time (minutes) |
Solution A
(%) |
Solution B
(%) |
Elution |
0 |
80 |
20 |
equilibration |
05 |
80 |
20 |
isocratic |
515 |
80®75 |
20®25 |
linear gradient |
1525 |
75 |
25 |
isocratic |
2530 |
75®55 |
25®45 |
linear gradient |
3038 |
55®0 |
45®100 |
linear gradient |
3845 |
0 |
100 |
isocratic |
Chromatograph the
Resolution solution, and record the peak responses as directed for
Procedure: the resolution,
R, between the
trans-
trans isomer and methyl benzenesulfonate is not less than 12.0. Chromatograph duplicate injections of the
Standard solution, and record the peak responses as directed for
Procedure: the responses for duplicate injections do not differ from each other by more than 12%.
Procedure
Separately inject equal volumes (about 100 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the methyl benzenesulfonate peaks: the peak response obtained from the Test solution is not greater than that obtained from the Standard solution. Not more than 0.01% of methyl benzenesulfonate is found.
Limit of toluene
Standard solution
Prepare a solution containing 100 µg of toluene per mL.
Procedure
Separately inject equal volumes (about 1 µL) of the Standard solution and the Test Solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks: the toluene peak from the Test Solution is not greater than the toluene peak obtained from the Standard solution. Not more than 0.5% of toluene is found.
Chromatographic purity
Buffer solution, Solution A, Solution B, and Mobile phase
Proceed as directed in the Assay.
Standard solution
Transfer 1.0 mL of the Standard preparation, prepared as directed in the Assay, to a 100-mL volumetric flask, dilute with Solution A to volume, and mix.
Test solution
Use the Assay preparation.
Chromatographic system (see Chromatography 621)
Prepare as directed in the
Assay. Chromatograph the
Standard solution, and record the peak responses as directed for
Procedure: the responses of the
cis-cis isomers from not fewer than two injections do not differ by more than 10%.
Procedure
Separately inject equal volumes (about 20 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure all of the peak responses, except the three main isomeric peaks. Calculate the percentage of each impurity in the portion of Atracurium Besylate taken by the formula:
10,000(C/W)(ri / rS),
in which
C is the concentration, in mg per mL, of the
cis-cis isomer in the
Standard solution; W is the weight, in mg, of Atracurium Besylate taken to prepare the
Test solution; ri is the peak response for each impurity obtained from the
Test solution; and
rS is the peak response for the
cis-cis isomer obtained from the
Standard solution: not more than 1.5% of any individual impurity is found, and not more than 3.5% of total impurities is found.
Assay
Buffer solution
Transfer about 10.2 g of monobasic potassium phosphate to a 1000-mL volumetric flask, and dissolve in about 950 mL of water. While stirring, adjust with phosphoric acid to a pH of 3.1, dilute with water to volume, and mix.
Solution A
Prepare a mixture of Buffer solution, acetonitrile, and methanol (75:20:5).
Solution B
Prepare a mixture of Buffer solution, methanol, and acetonitrile (50:30:20).
Mobile phase
Use variable mixtures of
Solution A and
Solution B as directed for
Chromatographic system. Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard preparation
Dissolve an accurately weighed quantity of
USP Atracurium Besylate RS in
Solution A to obtain a solution having a known concentration of about 1.0 mg per mL.
Assay preparation
Transfer about 100 mg of Atracurium Besylate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Solution A to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 280-nm detector and a 4.6-mm × 25-cm column that contains base-deactivated packing L1. The flow rate is about 1 mL per minute. The chromatograph is programmed as follows.
Time (minutes) |
Solution A
(%) |
Solution B
(%) |
Elution |
0 |
80 |
20 |
equilibration |
05 |
80 |
20 |
isocratic |
515 |
80®40 |
20®60 |
linear gradient |
1525 |
40 |
60 |
isocratic |
2530 |
40®0 |
60®100 |
linear gradient |
Chromatograph the
Standard preparation, and record the peak responses as directed for
Procedure: the relative retention times are about 0.8, 0.9, and 1.0 for the
trans-trans isomer, the
cis-trans isomer, and the
cis-cis isomer, respectively; the resolution,
R, between the
trans-trans isomer and the
cis-trans isomer and between the
cis-trans isomer and the
cis-cis isomer is not less than 1.1; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the three isomeric peaks. Calculate the quantity, in mg, of C
65H
82N
2O
18S
2 in the portion of Atracurium Besylate taken by the formula:
100C(rU / rs),
in which
C is the concentration, in mg per mL, of
USP Atracurium Besylate RS in the
Standard preparation; and
rU and
rs are the sums of the peak responses for the
trans-trans isomer, the
trans-cis isomer, and the
cis-cis isomer obtained from the
Assay preparation and the
Standard preparation, respectively.