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Primaquine Phosphate Tablets
» Primaquine Phosphate Tablets contain not less than 93.0 percent and not more than 107.0 percent of the labeled amount of C15H21N3O·2H3PO4.
Packaging and storage— Preserve in well-closed, light-resistant containers.
Identification— Digest a quantity of finely powdered Tablets, equivalent to about 25 mg of primaquine phosphate, with 10 mL of water for 15 minutes, and filter.
A: Dilute 0.1 mL of the filtrate with 1 mL of water, and add 1 drop of gold chloride TS: a violet-blue color is produced at once.
B: To the remainder of the filtrate add 5 mL of trinitrophenol TS: a yellow precipitate is formed. Wash the precipitate with cold water, and dry at 105 for 2 hours: the picrate melts between 208 and 215. [Caution—Picrates may explode.]
Dissolution 711—
Medium: 0.01 N hydrochloric acid; 900 mL.
Apparatus 2: 50 rpm.
Time: 60 minutes.
Determine the amount of C15H21N3O·2H3PO4 dissolved by employing the following method.
1-Pentanesulfonate sodium solution— Add about 961 mg of sodium 1-pentanesulfonate and 1 mL of glacial acetic acid to 400 mL of water, and mix.
Mobile phase— Prepare a filtered and degassed mixture of methanol and 1-Pentanesulfonate sodium solution (60:40). Make adjustments if necessary (see System Suitability under Chromatography 621).
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph replicate injections of the Standard solution and record the peak responses as directed for Procedure: the relative standard deviation is not more than 3.0%.
Procedure— Separately inject into the chromatograph equal volumes (about 20 µL) of the solution under test and a Standard solution having a known concentration of USP Primaquine Phosphate RS in the same Medium, and record the chromatograms. Measure the responses for the major peaks, and calculate the amount of C15H21N3O·2H3PO4 dissolved.
Tolerances— Not less than 80% (Q) of the labeled amount of C15H21N3O·2H3PO4 is dissolved in 60 minutes.
Uniformity of dosage units 905: meet the requirements.
Procedure for content uniformity— Transfer 1 Tablet, previously crushed or finely powdered, to a beaker, add 5 mL of hydrochloric acid and about 25 g of crushed ice, then add water to bring the total volume to about 50 mL. Proceed as directed under Nitrite Titration 451, beginning with “slowly titrate,” and using as the titrant 0.01 M sodium nitrite VS, freshly prepared from 0.1 M sodium nitrite. Concomitantly perform a blank titration, and make any necessary correction. Each mL of 0.01 M sodium nitrite is equivalent to 4.553 mg of C15H21N3O·2H3PO4.
Residual solvents 467: meet the requirements.
(Official January 1, 2007)
Assay— Weigh and finely powder not less than 30 Tablets. Weigh accurately a portion of the powder, equivalent to about 700 mg of primaquine phosphate, and transfer to a beaker. Add 50 mL of water and sufficient hydrochloric acid to provide about 5 mL in excess, and proceed as directed under Nitrite Titration 451, beginning with “cool to about 15.” Each mL of 0.1 M sodium nitrite is equivalent to 45.53 mg of C15H21N3O·2H3PO4.
Auxiliary Information— Staff Liaison : Behnam Davani, Ph.D., MBA, Senior Scientist
Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials
USP29–NF24 Page 1799
Phone Number : 1-301-816-8394