Alfuzosin Hydrochloride
(al fue' zoe sin hye'' droe klor' ide).
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C19H27N5O4·HCl 425.91

2-Furancarboxamide, N-[3-[(4-amino-6,7-dimethoxy-2-quinazolinyl)methylamino]propyl]tetrahydro-, monohydrochloride (±).
(±)-N-[3-[(4-Amino-6,7-dimethoxy-2-quinazolinyl)methylamino]propyl]tetrahydro-2-furamide monohydrochloride [81403-68-1].
» Alfuzosin Hydrochloride contains not less than 99.0 percent and not more than 101.0 percent of C19H27N5O4·HCl, calculated on the anhydrous basis.
Packaging and storage— Preserve in tight containers, protected from light and humidity. Store at room temperature.
USP Reference standards 11
USP Alfuzosin Hydrochloride RS Click to View Structure
USP Alfuzosin System Suitability Mixture RS
Alfuzosin Hydrochloride containing approximately 0.4% Impurity A (N-[3-[(4-amino-6,7-dimethoxyquinazolin-2-yl)(methyl)amino]propyl]furan-2-carboxamide); and about 0.4% Impurity D (N-(4-amino-6,7-dimethoxyquinazolin-2-yl)-N-methylpropane-1,3-diamine).
Identification—
B: It meets the requirements of the test for Chloride 191.
pH 791: between 4.0 and 5.5
Test solution: 20 mg per mL, in carbon dioxide-free water.
Optical rotation 781: 0.10 to +0.10
Test solution: 20 mg per mL, in carbon dioxide-free water.
Water, Method I 921: not more than 0.5%.
Residue on ignition 281: not more than 0.1%.
Related compounds—
Solution A— Dilute 5.0 mL of perchloric acid in 900 mL of water, adjust with 2 M sodium hydroxide solution to a pH of 3.5, and dilute with water to 1000 mL.
Mobile phase— Prepare a filtered and degassed mixture of Solution A, acetonitrile, and tetrahydrofuran (80:20:1). Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution— Dissolve an accurately weighed quantity of USP Alfuzosin System Suitability Mixture RS in Mobile phase, and dilute quantitatively with Mobile phase to obtain a solution containing about 0.4 mg per mL.
Test solution— Dissolve 40.0 mg of Alfuzosin Hydrochloride in Mobile phase, and dilute with Mobile phase to 100.0 mL.
Reference solution— Quantitatively dilute an accurately measured volume of the Test solution by a factor of 1000 with Mobile phase.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a detector set at 254 nm and a 4.6-mm × 15-cm column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the peak-to-valley ratio is at least 5. [note—The peak-to-valley ratio is determined as the ratio of the height above the baseline of the impurity A peak to the height above the baseline of the lowest point of the curve separating this impurity peak from the peak due to alfuzosin. ]
Procedure— Separately inject equal volumes (about 10 µL) of the Reference solution and the Test solution, record the chromatograms, and measure the peak responses. Calculate the percentage of each impurity in the portion of Alfuzosin Hydrochloride taken by the formula:
100[rU / (1000 rS)]
in which 100 is the percentage conversion factor; rU is the peak response for any impurity obtained from the Test solution; 1000 is the dilution factor; and rS is the peak response for alfuzosin obtained from the Reference solution: the limits are as shown in the accompanying table. Disregard any peak with an area less than 0.05%.
Compound Relative
Retention Time
Limit
(%)
Alfuzosin 1.0
Impurity A1 1.2 *
Impurity D2 0.5 0.20
Any individual unspecified impurity 0.10
Total impurities 0.30
1  N-[3-[(4-Amino-6,7-dimethoxyquinazolin-2-yl)(methyl)amino]propyl]furan-2-carboxamide.
2  N-(4-Amino-6,7-dimethoxyquinazolin-2-yl)-N-methylpropane-1,3-diamine.
*  Impurity A, a component of USP Alfuzosin System Suitability Mixture RS, is not a specified impurity.
Assay— Dissolve about 300 mg of Alfuzosin Hydrochloride, accurately weighed, in a mixture of 40 mL of anhydrous acetic acid and 40 mL of acetic anhydride. Titrate with 0.1 M perchloric acid, determining the endpoint potentiometrically. Each mL of 0.1 M perchloric acid is equivalent to 42.59 mg of C19H27N5O4·HCl.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Domenick Vicchio, Ph.D.
Senior Scientific Liaison
1-301-998-6828
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
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USP35–NF30 Page 2097
Pharmacopeial Forum: Volume No. 34(1) Page 69