TEST 1
Buffer solution
Prepare a solution in water containing 3.85 g per L of 1-pentanesulfonic acid, 2.9 g per L of sodium chloride, and 1% (v/v) of 1 N sulfuric acid.
Mobile phase
Prepare a filtered and degassed mixture of Buffer solution and acetonitrile (95:5).
System suitability solution
Dissolve accurately weighed quantities of citric acid and succinic acid in Mobile phase to obtain a solution containing about 0.5 mg of each per mL.
Standard solution
Dissolve an accurately weighed quantity of
USP Succinylmonocholine Chloride RS in
Mobile phase, and dilute quantitatively, and stepwise if necessary, with
Mobile phase to obtain a solution having a known concentration of about 0.05 mg per mL.
Test solution
Transfer about 100 mg of Succinylcholine Chloride, accurately weighed, to a 10-mL volumetric flask, and dissolve in and dilute with Mobile phase to volume.
Chromatographic system (see Chromatography 621)
The chromatograph is equipped with a 214-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. The flow rate is about 1 mL per minute. Samples are maintained at a temperature of about 4
during the analysis. Chromatograph the
System suitability solution, and record the peak responses as directed for
Procedure: the relative retention times are about 0.22 for succinic acid, 0.32 for the doublet of peaks quantitated as a single component, 0.49 for succinylmonocholine chloride, and 1.0 for succinylcholine chloride; the resolution,
R, between citric acid and succinic acid is not less than 2.9; and the relative standard deviation for replicate injections is not more than 3.0%.
Procedure
Separately inject equal volumes (about 50 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Begin integration after the edetate disodium peak, if present (retention time is about 3.5 minutes). Calculate the percentage of each impurity in the portion of Succinylcholine Chloride taken by the formula:
10C(ri / rS)F
in which
C is the concentration, in mg per mL, of
USP Succinylmonocholine Chloride RS in the
Standard solution; ri is the peak area for each impurity obtained from the
Test solution; rS is the succinylmonocholine chloride peak area obtained from the
Standard solution; and
F is the response factor (0.63 for succinic acid): not more than 0.1% of succinic acid is found; not more than 0.4% of the doublet of peaks quantitated as a single component is found; not more than 0.4% of succinylmonocholine chloride is found; and not more than 0.2% of any other individual impurity is found.
TEST 2 (Limit of choline)
Solution A
Prepare a solution in water containing 5% (v/v) of acetonitrile and 5% (w/v) of 0.1 M 1-hexanesulfonic acid.
Solution B
Prepare a solution of acetonitrile and water (1:1).
Mobile phase
Use variable amounts of
Solution A and
Solution B as directed for
Chromatographic system. Make adjustments if necessary (see
System Suitability under
Chromatography 621).
System suitability solution
Dissolve an accurately weighed quantity of
USP Choline Chloride RS and sodium chloride in water; and dilute quantitatively, and stepwise if necessary, with water to obtain a solution containing 0.05 mg per mL and
0.01
USP29 mg per mL, respectively.
Standard stock solution
Dissolve an accurately weighed quantity of
USP Choline Chloride RS in water; and dilute quantitatively, and stepwise if necessary, with water to obtain a solution containing 0.5 mg per mL.
Standard solution
Dilute 1 mL of the Standard stock solution with water to 50 mL.
Test solution
Transfer an accurately weighed quantity of Succinylcholine Chloride, about 50 mg, to a 25-mL flask. Dissolve in and dilute with water to volume.
Chromatographic system (see Chromatography 621)
The ion chromatograph is equipped with a suitable device for chemical suppression, a conductivity detector at 30 µS, and a 4.6-mm × 25-cm column that contains 5-µm packing L1. The eluant flow is about 1 mL per minute, and uses a suitable regenerant flow rate at 50 mA output. The chromatograph is programmed as follows.
Time (minutes) |
Solution A
(%) |
Solution B
(%) |
Elution |
015 |
100 |
0 |
isocratic |
1516 |
100®0 |
0®100 |
linear gradient |
1625 |
0 |
100 |
isocratic |
2527 |
0®100 |
100®0 |
linear gradient |
2740 |
100 |
0 |
isocratic |
Chromatograph the
System suitability solution, and record the peak responses as directed for
Procedure: the resolution,
R, between sodium and choline is not less than 2.0; and the relative standard deviation for replicate injections is not more than 3.0%.
Procedure
Separately inject equal volumes (about 50 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of choline in the portion of Succinylcholine Chloride taken by the formula:
37.5C(rC / rS)
in which
C is the concentration, in mg per mL, of
USP Choline Chloride RS in the
Standard solution; and
rC and
rS are the choline peak areas obtained from the
Test solution and the
Standard solution, respectively: not more than 0.3% of choline is found,
and
USP29 not more than 1.5% of total impurities is found, the results for
Test 1 and
Test 2 being added.