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C6H12N3PS 189.22

Aziridine, 1,1¢,1¢¢-phosphinothioylidynetris-.
Tris(1-aziridinyl)phosphine sulfide [52-24-4].
» Thiotepa contains not less than 97.0 percent and not more than 102.0 percent of C6H12N3PS, calculated on the anhydrous basis.
Caution—Great care should be taken to prevent inhaling particles of Thiotepa or exposing the skin to it.
Packaging and storage— Preserve in tight, light-resistant containers, and store in a refrigerator.
Identification, Infrared Absorption 197S
Solution: 3 in 400.
Medium: carbon disulfide.
Melting range 741: between 52 and 57.
Water, Method I 921: not more than 2.0%.
Mobile phase— Prepare a suitable filtered and degassed mixture of water and acetonitrile (9:1). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Dissolve an accurately weighed quantity of USP Thiotepa RS in Mobile phase to obtain a solution having a known concentration of about 1.5 mg per mL.
Assay preparation— Transfer about 75 mg of Thiotepa, accurately weighed, to a 50-mL volumetric flask, dissolve in Mobile phase, dilute with Mobile phase to volume, and mix.
Resolution solution— Transfer about 10 mg of USP Thiotepa RS to a 4-mL vial, add 2 mL of methanol, and mix. Add 50 µL of 0.1% phosphoric acid solution. Place a cap on the vial, and heat at 65 for 50 seconds. Cool the solution, add 1 mL of methanol, and mix.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 215-nm detector and a 4-mm × 15-cm column that contains packing L1. The flow rate is about 0.8 mL per minute. Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the relative retention times are about 1.25 for methoxythiotepa and 1.0 for thiotepa, and the resolution, R, between the methoxythiotepa peak and the thiotepa peak is not less than 3.0. Chromatograph the Standard preparation, and record the responses as directed for Procedure: the tailing factor for the thiotepa peak is not more than 1.8, the column efficiency is not less than 2600 theoretical plates, and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C6H12N3PS in the portion of Thiotepa taken by the formula:
50C(rU / rS)
in which C is the concentration, in mg per mL, of USP Thiotepa RS in the Standard preparation, and rU and rS are the thiotepa peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Feiwen Mao, M.S.
(MDOOD05) Monograph Development-Ophthalmics Oncologics and Dermatologicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 3730
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.