Phenelzine Sulfate
(fen' el zeen sul' fate).
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C8H12N2·H2SO4 234.27

Hydrazine, (2-phenylethyl)-, sulfate (1:1).
Phenethylhydrazine sulfate (1:1). [156-51-4].
» Phenelzine Sulfate contains not less than 98.0 percent and not more than 102.0 percent of C8H12N2·H2SO4, calculated on the dried basis.
Packaging and storage— Preserve in tight containers, protected from heat and light.
USP Reference standards 11
USP Phenelzine Sulfate RS Click to View Structure
Identification—
B: Dissolve 100 mg in 5 mL of water, render the solution alkaline with 1 N sodium hydroxide, and add 1 mL of alkaline cupric tartrate TS: a red to yellow-red precipitate is formed.
C: A solution (1 in 10) meets the requirements of the tests for Sulfate 191.
Melting range 741: between 164 and 168.
pH 791: between 1.4 and 1.9, in a solution (1 in 100).
Loss on drying 731 Dry it at a pressure not exceeding 5 mm of mercury over silica gel at 80 for 2 hours: it loses not more than 1.0% of its weight.
Limit of hydrazine—
Mobile phase— Prepare a filtered and degassed mixture of methanol and 1% monobasic ammonium phosphate solution (75:25). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution— Transfer an accurately weighed quantity of about 42.0 mg of hydrazine sulfate, equivalent to about 10 mg of hydrazine, to a 100-mL volumetric flask. Dissolve in water, sonicate for about 5 minutes, dilute with methanol to volume, and mix. Dilute an accurately measured volume of this solution quantitatively and stepwise with methanol to obtain a solution having a known concentration of 5.0 µg of hydrazine per mL. Transfer 5.0 mL of this solution to a 200-mL volumetric flask, add 50 mL of methanol and 0.7 mL of ammonium hydroxide, and shake to mix. Add 0.5 mL of salicylaldehyde, shake by mechanical means for about 5 minutes, dilute with methanol to volume, sonicate for about 2 minutes, and mix.
Test solution— Transfer about 25.8 mg of Phenelzine Sulfate, accurately weighed, to a 200-mL volumetric flask, dissolve in about 50 mL of methanol, and sonicate. Add 0.7 mL of ammonium hydroxide, shake to mix, add 0.5 mL of salicylaldehyde, shake by mechanical means for about 5 minutes, dilute with methanol to volume, sonicate for about 2 minutes, and mix.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 340-nm detector and a 4.6-mm × 25-cm column that contains 5-µm packing L1. Chromatograph the Standard solution, and record the peak areas as directed for Procedure: the relative retention times for salicylaldehyde, phenelzine sulfate derivative, and hydrazine sulfate derivative are about 0.21, 0.47, and 1.0, respectively; the column efficiency determined from the analyte peak is not less than 4500 theoretical plates; the resolution, R, between phenelzine and salazine (derivatized hydrazine) is not less than 1.25; and the relative standard deviation for replicate injections is not more than 7%.
Procedure— Separately inject equal volumes (about 50 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak areas for salazine (derivatized hydrazine). Calculate the percentage of hydrazine in the portion of Phenelzine Sulfate taken by the formula:
20(C/W)(rU / rS)
in which C is the concentration, in µg per mL, of hydrazine base in the Standard solution; W is the weight, in mg, of Phenelzine Sulfate taken to prepare the Test solution; and rU and rS are the salazine peak areas obtained from the Test solution and the Standard solution, respectively: not more than 0.1% is found.
Ordinary impurities 466
Test solution: a mixture of methanol and water (1:1).
Standard solution: a mixture of methanol and water (1:1).
Eluant: acetone. [Note—Prewash the plate with Eluant, and dry.]
Visualization: 1.
Assay—
Ion-pair solution, Mobile phase, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Phenelzine Sulfate Tablets.
Assay preparation— Transfer about 26 mg of Phenelzine Sulfate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
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 peak responses. Calculate the quantity, in mg, of C8H12N2·H2SO4 in the portion of Phenelzine Sulfate taken by the formula:
100C(rU / rS)
in which C is the concentration, in mg per mL, of USP Phenelzine Sulfate RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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Topic/Question Contact Expert Committee
Monograph Hariram Ramanathan, M.S.
Associate Scientific Liaison
1-301-816-8313
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
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USP35–NF30 Page 4282
Pharmacopeial Forum: Volume No. 27(1) Page 1814