(mye bole' er one).
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C20H30O2 302.46

Estr-4-en-3-one, 17-hydroxy-7,17-dimethyl-, (7,17)-.
17-Hydroxy-7,17-dimethylestr-4-en-3-one [3704-09-4].
» Mibolerone contains not less than 96.0 percent and not more than 106.0 percent of C20H30O2, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
Labeling— Label it to indicate that it is for veterinary use only.
USP Reference standards 11
USP Mibolerone RS Click to View Structure
Specific rotation 781S: between +34 and +40.
Test solution : 10 mg per mL, in chloroform.
Loss on drying 731 Dry about 1 g, accurately weighed, in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.5%.
Mobile phase— Prepare a filtered and degassed mixture of water, tetrahydrofuran, and methanol (60:25:15). Make adjustments if necessary (see System Suitability under Chromatography 621).
Internal standard solution— Prepare a solution of progesterone in methanol containing 0.6 mg per mL.
Standard preparation— Prepare a solution of USP Mibolerone RS in Internal standard solution having a known concentration of about 0.4 mg per mL. Mix, and sonicate if necessary to achieve complete solution.
Assay preparation— Transfer about 10 mg of Mibolerone, accurately weighed, to a 25-mL volumetric flask, dilute with Internal standard solution to volume, and mix. Sonicate if necessary to achieve complete solution.
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 the Standard preparation, and record the peak responses as directed for Procedure: the relative retention times are about 0.6 for mibolerone and 1.0 for progesterone; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Separately inject equal volumes (about 5 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 C20H30O2 in the portion of Mibolerone taken by the formula:
25C(RU / RS)
in which C is the concentration, in mg per mL, of USP Mibolerone RS in the Standard preparation; and RU and RS are the ratios of the peak responses of the mibolerone peak and the progesterone peak 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 Morgan Puderbaugh, B.S.
Associate Scientific Liaison
(SM32010) Monographs - Small Molecules 3
Reference Standards RS Technical Services
USP35–NF30 Page 3915