Phenylpropanolamine Bitartrate
(fen'' il proe'' pa nol' a meen bye tar' trate).
C9H13NO·C4H6O6 301.30

(R*,S*)-(±)--(1-Aminoethyl)benzenemethanol bitartrate [67244-90-0].
» Phenylpropanolamine Bitartrate contains not less than 98.0 percent and not more than 101.0 percent of C9H13NO·C4H6O6, calculated on the dried basis.
Packaging and storage— Preserve in tight, light-resistant containers.
USP Reference standards 11
USP Cathinone Hydrochloride RS
-Aminopropiophenone hydrochloride.
    C9H11NO·HCl    185.65
USP Dextroamphetamine Sulfate RS Click to View Structure
USP Phenylpropanediol RS
1-Phenyl-1,2-propanediol.
    C9H12O2    152.19
USP Phenylpropanolamine Bitartrate RS Click to View Structure
USP Phenylpropanolamine Hydrochloride RS Click to View Structure
Identification—
B: It responds to the test for Tartrate 191.
Melting range, Class I 741: between 150 and 164.
pH 791: between 3.1 and 3.7, in a solution (3 in 100).
Loss on drying 731 Dry it at 65 for 3 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Heavy metals, Method I 231 Dissolve 1 g in 5 mL of water, add 1 mL of 1 N acetic acid, and dilute with water to 25 mL: the limit is 0.002%.
Limit of cathinone hydrochloride— Proceed as directed for Limit of cathinone hydrochloride under Phenylpropanolamine Hydrochloride.
Limit of amphetamine hydrochloride and phenylpropanediol—
Mobile phase— Prepare a mixture of 20 mL of 10% tetramethylammonium hydroxide and 5 mL of phosphoric acid, dilute with water to a volume of 1000 mL, and mix. To 896 mL of the resulting solution add 100 mL of methanol, 4 mL of tetrahydrofuran, and mix. Filter and degas the mixture. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution A— Dissolve accurately weighed quantities of USP Phenylpropanolamine Hydrochloride RS and USP Dextroamphetamine Sulfate RS in water to obtain a solution having known concentrations of about 100 mg of USP Phenylpropanolamine Hydrochloride RS per mL and 1 µg of USP Dextroamphetamine Sulfate RS per mL.
Standard solution B— Dissolve an accurately weighed quantity of USP Phenylpropanediol RS in water, and dilute quantitatively, and stepwise if necessary, with water to obtain a solution having a known concentration of about 0.1 mg per mL.
Resolution solution— Dissolve accurately weighed quantities of USP Phenylpropanolamine Hydrochloride RS and USP Dextroamphetamine Sulfate RS in water to obtain a solution containing about 5 µg of each per mL.
Test solution— Transfer about 1000 mg of Phenylpropanolamine Bitartrate, accurately weighed, to a 10-mL volumetric flask, dilute with water 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 spherical 5-µm packing L1. The flow rate is about 2.0 mL per minute. Separately chromatograph the Resolution solution and each Standard solution, and record the peak responses as directed for Procedure: the relative retention times are about 1.0 for phenylpropanolamine, between 1.9 and 2.1 for dextroamphetamine, and between 2.3 and 2.7 for phenylpropanediol; the resolution, R, between phenylpropanolamine and dextroamphetamine in the chromatogram of the Resolution solution is not less than 5.0; and the relative standard deviation for replicate injections of the Standard solutions is not more than 3.0%.
Procedure— Separately inject equal volumes (about 20 µL) of Standard solution A, Standard solution B, and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the percentage of phenylpropanediol in the portion of Phenylpropanolamine Bitartrate taken by the formula:
1000C / W(rU / rS)
in which C is the concentration, in mg per mL, of USP Phenylpropanediol RS in Standard solution B; W is the weight, in mg, of Phenylpropanolamine Bitartrate taken to prepare the Test solution; and rU and rS are the peak responses obtained from the Test solution and the Standard solution B, respectively. The limit of phenylpropanediol is not more than 0.2%.
Calculate the percentage of amphetamine hydrochloride in the portion of Phenylpropanolamine Bitartrate taken by the formula:
(343.34 / 368.49)(C / W)(rU / rS)
in which 343.34 is twice the molecular weight of amphetamine hydrochloride; 368.49 is the molecular weight of dextroamphetamine sulfate; C is the concentration, in µg per mL, of USP Dextroamphetamine Sulfate RS in Standard solution A; W is the weight, in mg, of Phenylpropanolamine Bitartrate taken to prepare the Test solution; and rU and rS are the amphetamine peak responses obtained from the Test solution and Standard solution A, respectively. The limit of amphetamine hydrochloride is not more than 0.001%.
Assay— Dissolve about 500 mg of Phenylpropanolamine Bitartrate, previously dried and accurately weighed, in 50 mL of glacial acetic acid. Add 10 mL of mercuric acetate TS and 2 drops of crystal violet TS, and titrate with 0.1 N perchloric acid VS to a green endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 30.13 mg of C9H13NO·C4H6O6.
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Topic/Question Contact Expert Committee
Monograph Clydewyn M. Anthony, Ph.D.
Senior Scientific Liaison
1-301-816-8139
(SM22010) Monographs - Small Molecules 2
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 4302