A: Infrared Absorption á197Kñ.

B: Ultraviolet Absorption á197Uñ—

Solution: 0.5mg per mL.

Medium: water.

C: The retention time of the major peak in the chromatogram of the Assay preparationcorresponds to that of the Standard preparationobtained as directed in the Assay.

D: It responds to the tests for Chloride á191ñ.

Test solution: 100mg per mL,in water.

Buffer solution ,Mobile phase,and System suitability solution—Proceed as directed in the Assay.

Standard solution— Transfer 10.0mLof the System suitability solutionto a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Transfer 10.0mLof this solution to a 50mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Test solution— Transfer 50mg of Selegiline Hydrochloride to a 50-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,and mix.

Chromatographic system— Proceed as directed in the Assay.Inject about 20µLof the Standard solution,and record the peak responses as directed in the Procedure:the resolution,R,between the methamphetamine and selegiline peaks is not less than 3,and the relative standard deviation for replicate injections is not more than 5.0%.

Procedure— Separately inject equal volumes (about 20µL)of the Standard solutionand the Test solutioninto the chromatograph,and allow the Test solutionto elute for not less than three times the retention time of selegiline.Record the chromatograms,and measure the peak responses.Calculate the percentage of each impurity in the portion of Selegiline Hydrochloride taken by the formula: in which Cis the concentration,in mg per mL,of USP Selegiline Hydrochloride RSin the Standard solution,Wis the weight,in mg,of Selegiline Hydrochloride taken to prepare the Test solution,riis the peak response for each impurity in the chromatogram of the Test solution,and rSis the peak response for selegiline in the chromatogram of the Standard solution.Not more than 0.2%of any individual impurity is found,and the sum of all impurities is not more than 1.0%.

Buffer solution— Prepare a solution of 0.1Mmonobasic ammonium phosphate,adjust with phosphoric acid to a pHof 3.1,and mix.

Mobile phase— Prepare a filtered and degassed mixture of Buffer solutionand acetonitrile (80:20).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard preparation— Dissolve an accurately weighed quantity of USP Selegiline Hydrochloride RS,and dilute quantitatively,and stepwise if necessary,with Mobile phaseto obtain a solution having a known concentration of about 0.1mg per mL.

System suitability solution— Dissolve accurately weighed quantities of USP Methamphetamine Hydrochloride RSand USP Selegiline Hydrochloride RSin Mobile phaseto obtain a solution containing 0.1mg per mLof each Reference Standard.

Assay preparation— Transfer an accurately weighed quantity,about 50mg of Selegiline Hydrochloride,to a 50-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,and mix.Transfer 10.0mLof this solution to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 205-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 1mLper minute.Chromatograph the System suitability solution,and record the peak responses as directed for Procedure:the resolution,R,between the methamphetamine and selegiline peaks is not less than 3,and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C13H17N·HCl in the portion of Selegiline Hydrochloride taken by the formula: in which Cis the concentration,in mg per mL,of USP Selegiline Hydrochloride RSin the Standard preparation,and rUand rSare the selegiline peak responses obtained from the Assay preparationand the Standard preparation,respectively.