Primaquine Phosphate Tablets
»Primaquine Phosphate Tablets contain not less than 93.0percent and not more than 107.0percent 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 25mg of primaquine phosphate,with 10mLof water for 15minutes,and filter.
A: Dilute 0.1mLof the filtrate with 1mLof water,and add 1drop of gold chloride TS:a violet-blue color is produced at once.
B: To the remainder of the filtrate add 5mLof trinitrophenol TS:a yellow precipitate is formed.Wash the precipitate with cold water,and dry at 105for 2hours:the picrate melts between 208and 215.[Caution—Picrates may explode.]
Dissolution á711ñ—
Medium: 0.01Nhydrochloric acid;900mL.
Apparatus 2: 50rpm.
Time: 60minutes.
Determine the amount of C15H21N3O·2H3PO4dissolved by employing the following method.
1-Pentanesulfonate sodium solution— Add about 961mg of sodium 1-pentanesulfonate and 1mLof glacial acetic acid to 400mLof 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 Suitabilityunder Chromatography á621ñ).
Chromatographic system (see Chromatography á621ñ)—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 2mLper 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 20µL)of the solution under test and a Standard solution having a known concentration of USP Primaquine Phosphate RSin the same Medium,and record the chromatograms.Measure the responses for the major peaks,and calculate the amount of C15H21N3O·2H3PO4dissolved.
Tolerances— Not less than 80%(Q)of the labeled amount of C15H21N3O·2H3PO4is dissolved in 60minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Procedure for content uniformity— Transfer 1Tablet,previously crushed or finely powdered,to a beaker,add 5mLof hydrochloric acid and about 25g of crushed ice,then add water to bring the total volume to about 50mL.Proceed as directed under Nitrite Titration á451ñ,beginning with “slowly titrate,”and using as the titrant 0.01Msodium nitrite VS,freshly prepared from 0.1Msodium nitrite.Concomitantly perform a blank titration,and make any necessary correction.Each mLof 0.01Msodium nitrite is equivalent to 4.553mg of C15H21N3O·2H3PO4.
Assay— Weigh and finely powder not less than 30Tablets.Weigh accurately a portion of the powder,equivalent to about 700mg of primaquine phosphate,and transfer to a beaker.Add 50mLof water and sufficient hydrochloric acid to provide about 5mLin excess,and proceed as directed under Nitrite Titration á451ñ,beginning with “cool to about 15.”Each mLof 0.1Msodium nitrite is equivalent to 45.53mg of C15H21N3O·2H3PO4.
Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1619
Phone Number:1-301-816-8394