Medium: water;500mL.

Apparatus 1: 50rpm.

Time: 20minutes.

Monobasic ammonium phosphate solution— Dissolve 11.5g of monobasic ammonium phosphate in 1000mLof water.Adjust with 85%phosphoric acid to a pHof 3.1.

Mobile phase— Prepare a filtered and degassed mixture of Monobasic ammonium phosphate solutionand acetonitrile (4:1).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard solution— Transfer 25.0mg,accurately weighed,of USP Selegiline Hydrochloride RSto a 50-mLvolumetric flask.Dissolve in and dilute with water to volume,and mix.Pipet 2.0mLof this solution into a 100-mLvolumetric flask,dilute with water to volume,and mix.

Test solution— At 20minutes withdraw a 10-mLportion of the solution under test and centrifuge for 10minutes at 3500rpm.

Chromatographic system— The liquid chromatograph is equipped with a 205-nm detector and a 3.9-mm ×30-cm column that contains packing L1.Chromatograph the Standard solution,and record the peak responses.The relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 15µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the amount of C13H17N·HCl dissolved.

Tolerances— Not less than 80%(Q)of the labeled amount of C13H17N·HCl is dissolved in 20minutes.

Buffer solution ,Mobile phase,System suitability solution,and Chromatographic system—Proceed as directed in the test for Chromatographic purityunder Selegiline Hydrochloride.

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 20-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Test solution— Use a portion of the supernatant obtained from the Assay preparation.

Procedure— Proceed as directed in the test for Chromatographic purityunder Selegiline Hydrochloride.Calculate the percentage of each impurity,excluding methamphetamine hydrochloride,in the portion of Tablets taken by the formula: in which Wis the weight,in mg,of the labeled content of selegiline hydrochloride in the portion of Tablets taken to prepare the Test solution,and the other terms are as defined therein.Not more than 0.5%of any individual impurity is found,and the sum of all impurities,excluding methamphetamine hydrochloride,is not more than 2.0%.

Buffer solution ,Mobile phase,System suitability solution,Test solution,and Chromatographic system—Proceed as directed in the test for Chromatographic purityunder Selegiline Hydrochloride.

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

Procedure— Proceed as directed in the test for Chromatographic purityunder Selegiline Hydrochloride.Calculate the percentage of methamphetamine hydrochloride in the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Methamphetamine Hydrochloride RSin the Standard solution,Wis the weight,in mg,of the labeled content of selegiline hydrochloride in the portion of Tablets taken to prepare the Test solution,and rUand rSare the methamphetamine peak responses obtained from the Test solutionand the Standard solution,respectively.Not more than 2.0%of methamphetamine hydrochloride is found.

Buffer solution ,Mobile phase,Standard preparation,System suitability solution,and Chromatographic system—Proceed as directed in the test for Assayunder Selegiline Hydrochloride.

Assay preparation— Weigh and powder not less than 20Tablets.Transfer an accurately weighed portion of the powder equivalent to about 50mg of selegiline hydrochloride to a 50-mLvolumetric flask.Add 40mLof Mobile phase,sonicate for 10minutes,dilute with Mobile phaseto volume,and mix.Centrifuge a 25-mLaliquot of this solution at 3500rpm for 10minutes.[NOTE—Retain a portion of the supernatant for the Chromatographic purity and Limit of methamphetamine hydrochloride tests.]Transfer 10.0mLof the supernatant to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Procedure— Proceed as directed for Procedurein the Assayunder Selegiline Hydrochloride.Calculate the quantity,in mg,of C13H17N·HCl in the portion of Tablets taken by the formula: in which the terms are as defined therein.