Pheniramine Maleate
(fen ir' a meen mal' ee ate).
Click to View Image
C16H20N2·C4H4O4 356.42

2-[-[2-Dimethylaminoethyl]benzyl]pyridine bimaleate.
N,N-Dimethyl-3-phenyl-3-(2-pyridyl)propylamine hydrogen maleate [132-20-7].
» Pheniramine Maleate contains not less than 98.0 percent and not more than 102.0 percent of C16H20N2·C4H4O4, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11
USP Pheniramine Maleate RS Click to View Structure
Identification, Infrared Absorption 197K.
Melting range, Class I 741: between 104 and 109.
pH 791: between 4.5 and 5.5, in a solution (10 mg per mL).
Loss on drying 731 Dry it in vacuum at 65 for 6 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.5%.
Chromatographic purity—
0.005 M Octane sulfonic acid— Transfer 1.08 g of sodium 1-octane sulfonate to a 1-liter volumetric flask. Dilute with 1.5% (v/v) acetic acid solution to volume, add 5.0 mL of triethylamine, mix, and filter.
Mobile phase— Prepare a filtered and degassed mixture of 0.005 M Octane sulfonic acid and acetonitrile (39:11). Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve suitable quantities of phenylethyl alcohol and USP Pheniramine Maleate RS in water to obtain a solution containing about 3.6 and 0.24 mg per mL, respectively.
Test solution— Transfer about 24 mg of Pheniramine Maleate, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with water to volume, and mix.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 265-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.5 phenylethyl alcohol and 1.0 for pheniramine maleate, and the resolution, R, between phenylethyl alcohol and pheniramine maleate is not less than 2.0, the tailing factor is not more than 2.5, and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Inject a volume (about 10 µL) of the Test solution into the chromatograph, record the chromatogram, and measure the peak responses. Calculate the percentage of each impurity (not including the solvent peak and maleic acid, if observed) in the portion of Pheniramine Maleate taken by the formula:
100(ri / rs)
in which ri is the peak response for each impurity, and rs is the sum of the responses of all of the peaks: not more than 0.5% of any individual impurity is found, and not more than 2.0% of total impurities is found.
Assay— Dissolve about 500 mg of Pheniramine Maleate, accurately weighed, in 25 mL of glacial acetic acid. Add 2 drops of crystal violet TS, and titrate with 0.1 N perchloric acid VS. Perform a blank determination, and make any necessary corrections. Each mL of 0.1 N perchloric acid is equivalent to 17.82 mg of C16H20N2·C4H4O4.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Mary S. Waddell
Scientific Liaison
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
USP35–NF30 Page 4284