A: Infrared Absorption 197K.

B: Ultraviolet Absorption 197U—

Solution: 0.5 mg per mL.

Medium: water.

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

D: It responds to the tests for Chloride 191.

Test solution: 100 mg per mL, in water.

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

Standard solution— Transfer 10.0 mL of the System suitability solution to a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix. Transfer 10.0 mL of this solution to a 50 mL volumetric flask, dilute with Mobile phase to volume, and mix.

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

Chromatographic system— Proceed as directed in the Assay. Inject about 20 µL of 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 20 µL) of the Standard solution and the Test solution into the chromatograph, and allow the Test solution to 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 C is the concentration, in mg per mL, of USP Selegiline Hydrochloride RS in the Standard solution, W is the weight, in mg, of Selegiline Hydrochloride taken to prepare the Test solution, ri is the peak response for each impurity in the chromatogram of the Test solution, and rS is 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 0.1 M monobasic ammonium phosphate, adjust with phosphoric acid to a pH of 3.1, and mix.

Mobile phase— Prepare a filtered and degassed mixture of Buffer solution and acetonitrile (80:20). Make adjustments if necessary (see System Suitability under Chromatography 621).

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

System suitability solution— Dissolve accurately weighed quantities of USP Methamphetamine Hydrochloride RS and USP Selegiline Hydrochloride RS in Mobile phase to obtain a solution containing 0.1 mg per mL of each Reference Standard.

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

Chromatographic system (see Chromatography 621)—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 1 mL per 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 20 µL) of the Standard preparation and the Assay preparation into 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 C is the concentration, in mg per mL, of USP Selegiline Hydrochloride RS in the Standard preparation, and rU and rS are the selegiline peak responses obtained from the Assay preparation and the Standard preparation, respectively.