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C7H10N2OS 170.23

4(1H)-Pyrimidinone, 2,3-dihydro-6-propyl-2-thioxo-.
6-Propyl-2-thiouracil [51-52-5].
»Propylthiouracil contains not less than 98.0 percent and not more than 100.5 percent of C7H10N2OS, calculated on the dried basis.
Packaging and storage— Preserve in well-closed, light-resistant containers.
Identification, Infrared Absorption 197K.
Melting range 741: between 218 and 221.
Loss on drying 731 Dry it at 105 for 2 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.1%.
Selenium 291: 0.003%, a 200-mg specimen being used.
Ordinary impurities 466
Test solution: methanol.
Standard solution: methanol.
Application volume: 10 µL.
Eluant: a mixture of toluene, ethyl acetate, and formic acid (50:45:5), in a nonequilibrated chamber.
Visualization: 1.
Assay— Weigh accurately about 300 mg of Propylthiouracil, transfer to a 500-mL conical flask, and add 30 mL of water. Add from a buret about 30 mL of 0.1 N sodium hydroxide VS, heat to boiling, and agitate until solution is complete. Wash down any particles on the wall of the flask with a few mL of water, then add about 50 mL of 0.1 N silver nitrate while mixing, and boil gently for 7 minutes. Cool to room temperature, and continue to titrate with 0.1 N sodium hydroxide VS, determining the endpoint potentiometrically, using a glass-calomel electrode system. Each mL of 0.1 N sodium hydroxide is equivalent to 8.512 mg of C7H10N2OS.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Elena Gonikberg, Ph.D.
Senior Scientist
(MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 3434
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.