A: Infrared Absorption 197M.

B: Ultraviolet Absorption 197U—

Test solution: 120 mg per mL.

Test solution— Prepare a solution of Flunixin Meglumine in methanol containing 40 mg per mL.

Standard stock solution— Prepare a solution of USP Flunixin Meglumine RS in methanol containing 40 mg per mL.

Standard solution 1— Transfer 50 µL of the Standard stock solution to a 10-mL volumetric flask, dilute with methanol to volume, and mix.

Standard solution 2— Dilute 20 µL of the Standard stock solution with 10 mL of methanol, and mix.

Procedure— Separately apply 10-µL portions of the Test solution, the Stock standard solution, Standard solution 1, and Standard solution 2 to a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture. Allow the spots to dry, and in a paper-lined chamber develop the chromatogram in a solvent system consisting of a mixture of toluene, ethyl acetate, glacial acetic acid, and water (65:30:10:1) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the developing chamber, mark the solvent front, and air-dry the plate. Examine the plate under short-wavelength UV light. Compare the intensities of any secondary spots in the chromatogram obtained from the Test solution with the intensity of the principal spot in the chromatograms obtained from Standard solution 1 and from Standard solution 2: no individual secondary spot in the chromatogram obtained from the Test solution is more intense than the principal spot in the chromatogram obtained from Standard solution 2 (0.2%), and the sum of the intensities of all the secondary spots in the chromatogram obtained from the Test solution does not exceed the intensity of the principal spot in the chromatogram obtained from Standard solution 1 (0.5%).