A: Infrared Absorption á197Mñ.

B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation,as obtained in the Assay.

10M Ammonium acetate solution— Dissolve 77.1g of ammonium acetate in 100mLof water.

Mobile phase— Prepare a filtered and degassed mixture of methanol and 10M Ammonium acetate solution (9:1).Make adjustments if necessary (see System Suitability under Chromatography á621ñ).

Standard solution— Dissolve an accurately weighed quantity of USP Sumatriptan Succinate Related Compound A RSin Mobile phase,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 0.00625mg per mL.

Test solution— Transfer about 100mg of Sumatriptan,accurately weighed,to a 50-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,and mix.

Chromatographic system(see Chromatography á621ñ)— 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 2.0mLper 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 20µL)of the Standard solutionand the Test solution into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the percentage of sumatriptan related compound Ain the portion of Sumatriptan taken by the formula: in which 495.7and 613.8are the molecular weights of sumatriptan related compound Aand sumatriptan succinate related compound A,respectively;CSis the concentration,in mg per mL,of USP Sumatriptan Succinate Related Compound A RSin the Standard solution;CUis the concentration,in mg per mL,of Sumatriptan in the Test solution;and rUandrSare the peak responses for sumatriptan related compound Aobtained from the Test solution and the Standard solution,respectively:not more than 0.6%is found.

Diluentand System suitability solution— Proceed as directed in theAssay.

Buffer solution— Dissolve about 1.7mLof dibutylamine,about 0.6mLof phosphoric acid,and about 3.9g of monobasic sodium phosphate dihydrate in water.Adjust with a solution of 50%(w/v)sodium hydroxide to a pHof about 7.5,dilute with water to 1000mL,and mix.

Mobile phase— Prepare a filtered and degassed mixture of Buffer solution and acetonitrile (3:1).Make adjustments if necessary (seeSystem Suitability underChromatography á621ñ).

Identification solution— Prepare a solution of USP Sumatriptan Succinate Related Impurities RSinMobile phase having a concentration of about 3mg per mL.

Test solution— Dissolve an accurately weighed quantity of Sumatriptan in Diluentto obtain a solution having a concentration of about 2mg per mL.

Chromatographic system(see Chromatography á621ñ)— 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 1.5mLper minute.Chromatograph theSystem suitability solution,and record the peak responses as directed forProcedure:the relative retention times are about 0.9for sumatriptan succinate related compound Cand 1.0for sumatriptan;the resolution,R,between sumatriptan succinate related compound Cand sumatriptan is not less than 1.5.Chromatograph theIdentification solution,and record the peak responses as directed forProcedure:identify the peaks according toTable 1.

Procedure— Inject a volume (about 10µL)of theTest 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: in whichriis the peak response for each impurity,andrsis the sum of the responses of all the peaks:meets the requirements given inTable 1.

Diluent— Dissolve 3.9g of monobasic sodium phosphate dihydrate in water.Adjust with a solution of 50%(w/v)sodium hydroxide to a pHof about 6.5,and dilute with water to 1000mL.Mix 750mLof this solution with 250mLof acetonitrile.

Buffer solution— Dissolve about 1.7mLof dibutylamine,about 0.6mLof phosphoric acid,and about 3.9g of monobasic sodium phosphate dihydrate in water.Adjust with a solution of 50%(w/v)sodium hydroxide to a pHof about 6.5,dilute with water to 1000mL,and mix.

Mobile phase— Prepare a filtered and degassed mixture ofBuffer solution and acetonitrile (3:1).Make adjustments if necessary (seeSystem Suitability underChromatography á621ñ).

System suitability solution— Dissolve accurately weighed quantities of USP Sumatriptan Succinate RSand USP Sumatriptan Succinate Related Compound C RSin Diluentto obtain a solution having known concentrations of about 0.28mg per mLand 0.14mg per mL,respectively.

Standard preparation— Dissolve an accurately weighed quantity of USP Sumatriptan Succinate RSin Diluentto obtain a solution having a known concentration of about 0.14mg per mL.

Assay preparation— Transfer about 10mg of Sumatriptan,accurately weighed,to a 100-mLvolumetric flask.Dissolve in and dilute with Diluentto volume,and mix.

Chromatographic system(see Chromatography á621ñ)— 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 1.5mLper minute.Chromatograph theSystem suitability solution,and record the peak responses as directed forProcedure:the relative retention times are about 0.9for sumatriptan succinate related compound Cand 1.0for sumatriptan;and the resolution,R,between sumatriptan succinate related compound Cand sumatriptan is not less than 1.5.Chromatograph theStandard preparation,and record the peak responses as directed forProcedure:the relative standard deviation for replicate injections is not more than 1.5%.

Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the areas for the major peaks.Calculate the amount,in mg,of C14H21N3O2Sin the portion of Sumatriptan taken by the formula: in which 295.4and 413.5are the molecular weights of sumatriptan and sumatriptan succinate,respectively;Cis the concentration,in mg per mL,of USP Sumatriptan Succinate RSin the Standard preparation;and rUand rSare the peak responses for sumatriptan obtained from the Assay preparationand the Standard preparation,respectively.USP28