C12H17NO·C4H6O6 341.36

Morpholine,3,4-dimethyl-2-phenyl-,(2S-trans)-,[R-(R*,R*)]-2,3-dihydroxybutanedioate (1:1).
(2S,3S)-3,4-Dimethyl-2-phenylmorpholine L-(+)-tartrate (1:1) [50-58-8].

Packaging and storage— Preserve in tight containers.

USP Reference standards á11ñ— USP Phendimetrazine Tartrate RS.

Identification—

Melting range á741ñ: between 182and 188,with decomposition,but the range between beginning and end of melting does not exceed 3.

Specific rotation á781Sñ: between +32and +36.

pHá791ñ: between 3.0and 4.0,in a solution (1in 40).

Loss on drying á731ñ— Dry it to constant weight at 105:it loses not more than 0.5%of its weight.

Residue on ignition á281ñ: not more than 0.1%.

Chloride á221ñ— A1.0-g portion shows no more chloride than corresponds to 0.50mLof 0.020Nhydrochloric acid (0.035%).

Sulfate á221ñ— A1.0-g portion shows no more sulfate than corresponds to 0.10mLof 0.020Nsulfuric acid (0.01%).

Heavy metals á231ñ: 0.001%.

Chromatographic purity— Dissolve 500mg in water,dilute with water to 5.0mL,and mix.Apply 10µLof this preparation and 10µLof an aqueous solution of USP Phendimetrazine Tartrate RScontaining about 100mg per mLto the starting line to a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Develop the chromatogram in a suitable chamber with a solvent system consisting of a mixture of acetone,methanol,and ammonium hydroxide (50:50:1)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,air-dry,view under short-wavelength UVlight,and observe the location of the spots.Expose the plate to iodine vapors in a closed chamber:yellow spots appear at the same locations as the spots observed under UVlight,and the RFvalue of the spot obtained from the test preparation corresponds to that obtained from the Standard solution,and no other spot is obtained.

Organic volatile impurities,Method Iá467ñ: meets the requirements.

L-erythro isomer— Dissolve 3.0g of Phendimetrazine Tartrate in 25mLof sodium hydroxide solution (1in 20)in a suitable separator.Add 25mLof sodium hydroxide solution (1in 2),swirl,and allow the phendimetrazine base to separate.Discard the lower,alkaline layer,and collect the upper layer,centrifuging,if necessary,to obtain a clear liquid.Inject 1.0µLof this liquid into a suitable gas chromatograph equipped with a flame-ionization detector,a 100:1specimen splitter,and a 25-m ×0.25-mm capillary column,the inside wall of which is coated with a 0.4-µm film of liquid phase G1.The temperatures of the injection port,column,and detector block are 250,140,and 280,respectively.The carrier gas is helium.Preferably using an electronic integrator,determine the areas of all peaks in the chromatogram.The retention times are about 8.5minutes for the D-threoisomer and 9minutes for the L-erythroisomer.Calculate the percentage of L-erythroisomer in the test specimen taken by the formula: in which rUis the peak area response of the L-erythroisomer peak and rSis the sum of the areas of the L-erythroisomer peak and the D-threoisomer peak:the limit is 0.1%.

Assay— Transfer to a beaker about 500mg of Phendimetrazine Tartrate,accurately weighed,and dissolve in 50mLof glacial acetic acid.Add 1drop of crystal violet TS,and titrate with 0.1Nperchloric acid VSto a green endpoint.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 34.14mg of C12H17NO·C4H6O6.

Expert Committee:(PA2)Pharmaceutical Analysis 2

USP28–NF23Page 1525

Phone Number:1-301-816-8143