(tol' met in soe' dee um).
1H-Pyrrole-2-acetic acid, 1-methyl-5-(4-methylbenzoyl)-, sodium salt, dihydrate.
Sodium 1-methyl-5-p-toluoylpyrrole-2-acetate dihydrate [64490-92-2].
Anhydrous 279.27 [35711-34-3].
» Tolmetin Sodium contains not less than 98.0 percent and not more than 102.0 percent of C15H14NNaO3, calculated on the dried basis.
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
B: Ultraviolet Absorption 197U
Solution: 10 µg per mL.
Medium: pH 7 phosphate buffer (see Buffer solutions in the section Reagents, Indicators, and Solutions.)
C: A solution (1 in 20) responds to the tests for Sodium 191.
Loss on drying 731 Dry it in vacuum at 60 for 4 hours: it loses between 10.4% and 12.4% of its weight.
Heavy metals, Method II 231: 0.002%.
Chromatographic purity Dissolve 125 mg in 10 mL of methanol to obtain the Test solution. Dissolve USP Tolmetin Sodium RS in methanol to obtain a Standard solution having a concentration of 12.5 mg per mL. Dilute a portion of this Standard solution quantitatively with methanol to obtain a Diluted standard solution having a concentration of 62.5 µg per mL. Apply separate 20-µL portions of the three solutions on the starting line to a suitable thin-layer chromatographic plate (see Chromatography 621) coated with 0.25-mm layer of chromatographic silica gel mixture. Develop the chromatogram in a solvent system consisting of a mixture of chloroform and glacial acetic acid (95:5) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, mark the solvent front, air-dry, and view under short-wavelength UV light: the RF value of the principal spot from the Test solution corresponds to that from the Standard solution. Any other spot obtained from the Test solution does not exceed in size or intensity the principal spot obtained from the Diluted standard solution (0.5%), and the sum of the total impurities based on a comparison of the intensities of all such other spots with the Diluted standard solution does not exceed 2.0%.
Assay Dissolve, by warming, about 300 mg of Tolmetin Sodium, accurately weighed, in 150 mL of glacial acetic acid. Cool to room temperature, and titrate with 0.1 N perchloric acid VS, determining the endpoint electrometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 27.93 mg of C15H14NNaO3.
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USP35NF30 Page 4895