Methyltestosterone Capsules
» Methyltestosterone Capsules contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of methyltestosterone (C20H30O2).
Packaging and storage— Preserve in well-closed containers.
USP Reference standards 11
USP Methyltestosterone RS Click to View Structure
Identification— Evaporate 25 mL of the first alcohol solution of methyltestosterone obtained in the Assay to dryness: the IR absorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima at the same wavelengths as that of a similar preparation of USP Methyltestosterone RS.
Dissolution 711
Medium: water; 900 mL.
Apparatus 1: 100 rpm.
Time: 45 minutes.
Procedure— Determine the amount in solution on filtered portions of the Medium, suitably diluted quantitatively and stepwise with water to obtain a solution containing about 10 µg of methyltestosterone per mL at the wavelength of maximum absorbance at about 248 nm, with a suitable spectrophotometer, in comparison with a solution of USP Methyltestosterone RS in the same medium at the same concentration, water being used as the blank.
Tolerances— Not less than 70% (Q) of the labeled amount of C20H30O2 is dissolved in 45 minutes.
Uniformity of dosage units 905: meet the requirements.
Procedure for content uniformity— Transfer the contents of 1 Capsule to a 100-mL volumetric flask, add 50 mL of methanol, and shake by mechanical means for 60 minutes. Dilute with methanol to volume, and filter, discarding the first 20 mL of the filtrate. Dilute a portion of the subsequent filtrate quantitatively and stepwise, if necessary, with methanol to obtain a solution containing about 10 µg of methyltestosterone per mL. Concomitantly determine the absorbances of this solution and a Standard solution of USP Methyltestosterone RS in the same medium having a known concentration of about 10 µg per mL, in 1-cm cells at the wavelength of maximum absorbance at about 241 nm, with a suitable spectrophotometer, using methanol as the blank. Calculate the quantity, in mg, of C20H30O2 in the Capsule taken by the formula:
(T / D)C(AU / AS)
in which T is the labeled quantity, in mg, of methyltestosterone in the Capsule; D is the concentration, in µg per mL, of methyltestosterone in the solution from the Capsule, based on the labeled quantity per Capsule and the extent of dilution; C is the concentration, in µg per mL, of USP Methyltestosterone RS in the Standard solution; and AU and AS are the absorbances of the solution from the Capsule and the Standard solution, respectively.
Assay— Remove as completely as possible and weigh the contents of not less than 20 Capsules, and mix. Transfer an accurately weighed portion of the powder, equivalent to about 10 mg of methyltestosterone, to a 125-mL separator with the aid of about 5 mL of water. Extract with four 20-mL portions of chloroform, filtering each through chloroform-washed cotton. Evaporate the combined extracts on a steam bath, with the aid of a current of air, to dryness. Dissolve the residue in alcohol, transfer to a 50-mL volumetric flask, add alcohol to volume, and mix. Pipet a 5-mL aliquot into a 100-mL volumetric flask, add alcohol to volume, and mix. Concomitantly determine the absorbances of this solution and a Standard solution of USP Methyltestosterone RS in the same medium having a known concentration of about 10 µg per mL, in 1-cm cells at the wavelength of maximum absorbance at about 241 nm, with a suitable spectrophotometer, using alcohol as the blank. Calculate the quantity, in mg, of methyltestosterone (C20H30O2) in the portion of Capsules contents taken by the formula:
C(AU / AS)
in which C is the concentration, in µg per mL, of USP Methyltestosterone RS in the Standard solution; and AU and AS are the absorbances of the solution from the Capsules and the Standard solution, respectively.
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Topic/Question Contact Expert Committee
Monograph Mary S. Waddell
Scientific Liaison
1-301-816-8124
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
1-301-816-8106
(GCDF2010) General Chapters - Dosage Forms
USP35–NF30 Page 3890