Limit of sumatriptan related compound A
10 M Ammonium acetate solution
Dissolve 77.1 g of ammonium acetate in 100 mL of water.
Mobile phase
Prepare a filtered and degassed mixture of methanol and
10 M Ammonium acetate solution (9:1). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Standard solution
Dissolve an accurately weighed quantity of USP Sumatriptan Succinate Related Compound A RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.00625 mg per mL.
Test solution
Transfer about 100 mg of Sumatriptan, accurately weighed, to a 50-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 282-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L3. The flow rate is about 2.0 mL per minute. Chromatograph the
Standard solution, and record the peak responses as directed for
Procedure: the relative standard deviation for replicate injections is not more than 5%.
Procedure
Separately inject equal volumes (about 20 µL) of the
Standard solution and the
Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of sumatriptan related compound A in the portion of Sumatriptan taken by the formula:
100(495.7/613.8)(CS /CU)(rU /rS),
in which 495.7 and 613.8 are the molecular weights of sumatriptan related compound A and sumatriptan succinate related compound A, respectively;
CS is the concentration, in mg per mL, of USP Sumatriptan Succinate Related Compound A RS in the
Standard solution; CU is the concentration, in mg per mL, of Sumatriptan in the
Test solution; and
rU and
rS are the peak responses for sumatriptan related compound A obtained from the
Test solution and the
Standard solution, respectively: not more than 0.6% is found.
Related compounds
Diluent and System suitability solution
Proceed as directed in the Assay.
Buffer solution
Dissolve about 1.7 mL of dibutylamine, about 0.6 mL of phosphoric acid, and about 3.9 g of monobasic sodium phosphate dihydrate in water. Adjust with a solution of 50 % (w/v) sodium hydroxide to a pH of about 7.5, dilute with water to 1000 mL, and mix.
Mobile phase
Prepare a filtered and degassed mixture of
Buffer solution and acetonitrile (3:1). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
Identification solution
Prepare a solution of USP Sumatriptan Succinate Related Impurities RS in Mobile phase having a concentration of about 3 mg per mL.
Test solution
Dissolve an accurately weighed quantity of Sumatriptan in Diluent to obtain a solution having a concentration of about 2 mg per mL.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 282-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the
System suitability solution, and record the peak responses as directed for
Procedure: the relative retention times are about 0.9 for sumatriptan succinate related compound C and 1.0 for sumatriptan; the resolution,
R, between sumatriptan succinate related compound C and sumatriptan is not less than 1.5. Chromatograph the
Identification solution, and record the peak responses as directed for
Procedure: identify the peaks according to
Table 1.
Table 1
Compound Name |
Relative Retention Time |
Limit (%) |
[3-[2-(Dimethylamino N-oxide)ethyl]-1H-indol-5-yl]-N-methylmethanesulfonamide |
about 0.3 |
0.2 |
[3-[2-(Methylamino)ethyl]-1H-indol-5-yl]-N-methylmethanesulfonamide |
about 0.6 |
0.5 |
Sumatriptan succinate related compound C |
about 0.9 |
0.5 |
Sumatriptan |
1.0 |
|
[3-[2-(Aminoethyl)-1H-indol-5-yl]-N-methylmethanesulfonamide |
about 0.4 |
0.1 |
Unknown impurities |
|
0.1 |
Total |
|
1.5 |
[NOTEThe calculation of total impurities includes the amount of sumatriptan related compound A, determined in the test for Limit of sumatriptan related compound A.] |
Procedure
Inject a volume (about 10 µL) of the
Test solution into the chromatograph, record the chromatogram, and measure all of the peak responses. Calculate the percentage of each impurity in the portion of Sumatriptan taken by the formula:
100(ri / rs),
in which
ri is the peak response for each impurity, and
rs is the sum of the responses of all the peaks: meets the requirements given in
Table 1.
Assay
Diluent
Dissolve 3.9 g of monobasic sodium phosphate dihydrate in water. Adjust with a solution of 50 % (w/v) sodium hydroxide to a pH of about 6.5, and dilute with water to 1000 mL. Mix 750 mL of this solution with 250 mL of acetonitrile.
Buffer solution
Dissolve about 1.7 mL of dibutylamine, about 0.6 mL of phosphoric acid, and about 3.9 g of monobasic sodium phosphate dihydrate in water. Adjust with a solution of 50 % (w/v) sodium hydroxide to a pH of about 6.5, dilute with water to 1000 mL, and mix.
Mobile phase
Prepare a filtered and degassed mixture of
Buffer solution and acetonitrile (3:1). Make adjustments if necessary (see
System Suitability under
Chromatography 621).
System suitability solution
Dissolve accurately weighed quantities of USP Sumatriptan Succinate RS and USP Sumatriptan Succinate Related Compound C RS in Diluent to obtain a solution having known concentrations of about 0.28 mg per mL and 0.14 mg per mL, respectively.
Standard preparation
Dissolve an accurately weighed quantity of USP Sumatriptan Succinate RS in Diluent to obtain a solution having a known concentration of about 0.14 mg per mL.
Assay preparation
Transfer about 10 mg of Sumatriptan, accurately weighed, to a 100-mL volumetric flask. Dissolve in and dilute with Diluent to volume, and mix.
Chromatographic system (see Chromatography 621)
The liquid chromatograph is equipped with a 282-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the
System suitability solution, and record the peak responses as directed for
Procedure: the relative retention times are about 0.9 for sumatriptan succinate related compound C and 1.0 for sumatriptan; and the resolution,
R, between sumatriptan succinate related compound C and sumatriptan is not less than 1.5. Chromatograph the
Standard preparation, and record the peak responses as directed for
Procedure: the relative standard deviation for replicate injections is not more than 1.5%.
Procedure
Separately inject equal volumes (about 10 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the areas for the major peaks. Calculate the amount, in mg, of C
14H
21N
3O
2S in the portion of Sumatriptan taken by the formula:
(295.4/413.5)100C(rU / rS),
in which 295.4 and 413.5 are the molecular weights of sumatriptan and sumatriptan succinate, respectively;
C is the concentration, in mg per mL, of USP Sumatriptan Succinate RS in the
Standard preparation; and
rU and
rS are the peak responses for sumatriptan obtained from the
Assay preparation and the
Standard preparation, respectively.