Ergoloid Mesylates
C35H41N5O5·CH4O3S (dihydroergocristine mesylate)
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C32H43N5O5·CH4O3S (dihydro-
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C32H43N5O5·CH4O3S (dihydro-
![]() ![]() ![]() ![]() ![]() ![]() Ergotaman-3¢,6¢,18-trione, 9,10-dihydro-12¢-hydroxy-2¢,5¢-bis(1-methylethyl)-, (5¢ ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Dihydroergotoxine monomethanesulfonate (salt). An equiproportional mixture of dihydroergocornine mesylate, dihydroergocristine mesylate, and ratio of dihydro- ![]() ![]() ![]() ![]() ![]() » Ergoloid Mesylates is a mixture of the methanesulfonate salts of the three hydrogenated alkaloids, dihydroergocristine (C35H41N5O5·CH4O3S), dihydroergocornine (C31H41N5O5·CH4O3S), and dihydroergocryptine (C32H43N5O5·CH4O3S), in an approximate weight ratio of 1:1:1. Ergoloid Mesylates contains not less than 97.0 percent and not more than 103.0 percent of the alkaloid methanesulfonate mixture, calculated on the anhydrous basis, and not less than 30.3 percent and not more than 36.3 percent of the methanesulfonate salt of each of the individual alkaloids. Dihydroergocryptine mesylate exists as a mixture of alpha- and beta- isomers. The ratio of alpha- to beta- isomers is not less than 1.5:1.0 and not more than 2.5:1.0.
Packaging and storage
Preserve in tight, light-resistant containers.
Identification
A:
The IR absorption spectrum of a potassium bromide dispersion of it exhibits maxima only at the same wavelengths as that of a similar, undried preparation of USP Ergoloid Mesylates RS.
B:
In a suitable chromatographic chamber, arranged for thin-layer chromatography, place a volume of a solvent system consisting of a mixture of acetone, n-butyl alcohol, ammonium hydroxide, and water (65:20:10:5) sufficient to develop the chromatogram. Prepare a test solution of Ergoloid Mesylates in a mixture of chloroform and methanol (9:1) containing 40 mg per mL. Apply 10 µL of this solution and 10 µL of a reference solution of methanesulfonic acid containing 0.4 mL in 100 mL of a mixture of chloroform and methanol (9:1) to a suitable thin-layer chromatographic plate (see Chromatography
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Specific rotation
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Test solution:
10 mg per mL, in dilute alcohol (1 in 2).
pH
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Water, Method I
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Limit of ergotamine
Prepare three solutions in a mixture of chloroform and methanol (9:1) containing 5 mg of Ergoloid Mesylates per mL, 5 mg of USP Ergoloid Mesylates RS per mL, and 5 mg of Ergotamine Tartrate per mL. Apply 5-µL volumes of the solutions at points about 2 cm from the bottom edge of a thin-layer chromatographic plate (see Chromatography
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Limit of nonhydrogenated alkaloids
Prepare a solution in alcohol containing 0.4 mg of Ergoloid Mesylates per mL, and prepare a 1 in 10 dilution of the first solution. Determine the absorbances in 1-cm cells of the first solution at 317.5 nm and the dilution at 280 nm, using alcohol as the blank: the absorbance of the first solution is not more than 0.15 times that of the dilution.
Assay
Mobile phase
Prepare a degassed solution containing a mixture of water, acetonitrile, and triethylamine (80:20:2.5). Adjust the ratio as necessary.
Standard preparation
Transfer about 10 mg of USP Ergoloid Mesylates RS, accurately weighed, to a 10-mL volumetric flask. Dissolve in a mixture of acetonitrile and water (1:1), dilute with the same solvent to volume, and mix. Prepare this solution fresh.
Assay preparation
Using about 10 mg of Ergoloid Mesylates, accurately weighed, proceed as directed for Standard preparation.
Chromatographic system
(see Chromatography
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Procedure
Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph by means of a suitable microsyringe or sampling valve, record the chromatograms, and measure the responses for the major peaks. The order of elution is dihydroergocornine, dihydro-
![]() ![]() 10C(rU / rS)
in which C is the concentration, in mg per mL, of USP Ergoloid Mesylates RS in the Standard preparation; and rU and rS are the sums of the responses of the four major peaks obtained from the Assay preparation and the Standard preparation, respectively.
Calculate the percentage of each alkaloid taken by the formula:
100ri(MW)i / S[ri(MW)i]
in which ri is the peak response of an individual alkaloid; (MW)i is the molecular weight of that alkaloid; and S[ri(MW)i] is the summation of the products of peak responses and molecular weights calculated for the four alkaloids.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
Chromatographic Column
USP32NF27 Page 2271
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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