Benzeneethanamine, -methyl-, (S)-, sulfate (2:1).
(+)--Methylphenethylamine sulfate (2:1) [51-63-8].
» Dextroamphetamine Sulfate, the dextrorotatory isomer of amphetamine sulfate, contains not less than 98.0 percent and not more than 101.0 percent of (C9H13N)2·H2SO4, calculated on the dried basis.
Packaging and storage Preserve in well-closed containers.
A: Dissolve about 100 mg in 5 mL of water, add 5 mL of 1 N sodium hydroxide, cool to 10 to 15, add 1 mL of a mixture of 1 volume of benzoyl chloride and 2 volumes of anhydrous ethyl ether, insert the stopper, and shake for 3 minutes. Filter the precipitate, wash it with about 10 mL of cold water, and recrystallize it from diluted alcohol: the crystals of the benzoyl derivative of dextroamphetamine so obtained, after being dried at 105 for 3 hours, melt between 155 and 160.
B: A solution (1 in 10) responds to the tests for Sulfate 191.
Specific rotation 781S: between +20 and +23.5.
Test solution: 40 mg per mL, in water.
pH 791: between 5.0 and 6.0, in a solution (1 in 20).
Loss on drying 731 Dry it at 105 for 2 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Diluent Dilute 3.12 mL of phosphoric acid with water to 1000 mL.
Buffer solution Dissolve 2.16 g of sodium 1-octanesulfonate in 1000 mL of water, and add 1.0 mL of triethylamine. Mix, and adjust with phosphoric acid to a pH of 2.5.
Mobile phase Prepare a filtered and degassed mixture of Buffer solution, acetonitrile, and methanol (144:37:19). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard stock solution Dissolve an accurately weighed quantity of USP Dextroamphetamine Sulfate RS in Diluent to obtain a solution having a known concentration of about 0.3 mg per mL.
Standard solution Dilute an accurately measured volume of Standard stock solution in Diluent to obtain a solution having a known concentration of about 0.003 mg per mL.
Test solution Transfer about 30 mg of Dextroamphetamine Sulfate, accurately weighed, to a 100-mL volumetric flask. Dissolve in 50 mL of Diluent, sonicate for 5 minutes, dilute with Diluent to volume, and mix.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 215-nm detector and a 4.6-mm × 15-cm column that contains 5-µm packing L1. The flow rate is about 1 mL per minute. Chromatograph the Standard stock solution, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%. Chromatograph the Test solution, and record the peak responses as directed for Procedure: the resolution, R, between dextroamphetamine and any adjacent peak is not less than 1.5.
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 responses. Calculate the percentage of each impurity in the portion of Dextroamphetamine Sulfate taken by the formula:
10,000(C/W)(ri / rS)in which C is the concentration, in mg per mL, of USP Dextroamphetamine Sulfate RS in the Standard solution; W is the weight, in mg, of Dextroamphetamine Sulfate taken to prepare the Test solution; ri is the peak response for each impurity obtained from the Test solution; and rS is the peak response for amphetamine obtained from the Standard solution: not more than 0.1% of any individual impurity is found; and not more than 0.5% of total impurities is found.
Assay Dissolve about 500 mg of Dextroamphetamine Sulfate, accurately weighed, in 50 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 36.85 mg of (C9H13N)2·H2SO4.
Auxiliary Information Please check for your question in the FAQs before contacting USP.Chromatographic Column
USP32NF27 Page 2103Pharmacopeial Forum: Volume No. 34(4) Page 921
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.