Methylprednisolone
Pregna-1,4-diene-3,20-dione, 11,17,21-trihydroxy-6-methyl-, (6 ![]() ![]() 11 ![]() ![]() ![]() ![]() ![]() » Methylprednisolone contains not less than 97.0 percent and not more than 103.0 percent of C22H30O5, calculated on the dried basis.
Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
B:
Ultraviolet Absorption
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Solution:
10 µg per mL.
Medium:
alcohol.
Absorptivities at 243 nm, calculated on the dried basis, do not differ by more than 3.0%.
C:
Dissolve about 5 mg in 2 mL of sulfuric acid: a red color is produced.
Loss on drying
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Residue on ignition
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Change to read:
Chromatographic purity—
Mobile phase—
Prepare a filtered and degassed mixture of water, tetrahydrofuran, dimethyl sulfoxide, and butanol (149:40:10:1). Make adjustments if necessary (see System Suitability in Chromatography
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Diluting solution—
Prepare a filtered mixture of water, tetrahydrofuran, and glacial acetic acid (72:25:3).
Standard solution—
Dissolve an accurately weighed quantity of USP Methylprednisolone RS in Diluting solution. Dilute quantitatively, and stepwise if necessary, with Diluting solution to obtain a solution having a known concentration of about 0.01 mg per mL.
Test solution—
Transfer about 25 mg of Methylprednisolone, accurately weighed, to a 25-mL volumetric flask, dissolve in and dilute with Diluting solution to volume, and mix.
Chromatographic system
(see Chromatography
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Procedure—
Separately inject equal volumes (about 10 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the percentage of each impurity in the portion of Methylprednisolone taken by the formula:
![]() 100(CS / CU)(ri / rS)
in which CS and CU are the concentrations, in mg per mL, of Methylprednisolone in the Standard solution and the Test solution, respectively;![]()
Change to read:
Assay—
Mobile phase—
Prepare a solution containing a mixture of butyl chloride, water-saturated butyl chloride, tetrahydrofuran, methanol, and glacial acetic acid (475:475:70:35:30).
Internal standard solution—
Dissolve prednisone in a 3 in 100 solution of glacial acetic acid in chloroform to obtain a solution having a concentration of about 0.2 mg per mL.
Standard preparation—
Dissolve an accurately weighed quantity of USP Methylprednisolone RS in Internal standard solution to obtain a solution having a known concentration of about 0.2 mg per mL.
Assay preparation—
Using about 10 mg of Methylprednisolone, accurately weighed, proceed as directed for Standard preparation.
Chromatographic system
(see Chromatography
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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: the relative retention times are about 0.7 for prednisone and 1.0 for methylprednisolone. Calculate the quantity,
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
Chromatographic Column—
USP32–NF27 Page 2951
Pharmacopeial Forum: Volume No. 33(6) Page 1189
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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