A: Infrared Absorption 197K.

B: Ultraviolet Absorption 197U—

C: The RF value and intensity of the principal spot obtained from the chromatogram of Test solution 2 correspond to those obtained from the chromatogram of Standard solution 1, as obtained in the test for Related compounds.

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.

Test solution 1— Dissolve about 200 mg of Tinidazole, accurately weighed, in 10 mL of methanol.

Test solution 2— Transfer 1.0 mL of Test solution 1 to a 10-mL volumetric flask, dilute with methanol to volume, and mix.

Standard solution 1— Prepare a solution of USP Tinidazole RS in methanol containing 2.0 mg per mL.

Standard solution 2— Dilute 1.0 mL of Standard solution 1 with methanol to 20 mL.

Standard solution 3— Dilute 4.0 mL of Standard solution 2 with methanol to 10 mL.

Standard solution 4— Prepare a solution of USP Tinidazole Related Compound A RS in methanol containing 0.1 mg per mL.

Standard solution 5— Prepare a solution of USP Tinidazole Related Compound B RS in methanol containing 0.1 mg per mL.

Application volume: 10 µL.

Developing solvent system: a mixture of ethyl acetate and butyl alcohol (3:1).

Procedure— Proceed as directed for Thin-Layer Chromatography under Chromatography 621. Activate the plate for at least 1 hour at 110. Examine the plate under short-wavelength UV light: any spots due to tinidazole related compound A and tinidazole related compound B obtained from Test solution 1 are no more intense than the corresponding spots obtained from Standard solution 4 and Standard solution 5, respectively; any spot, other than the principal spot, obtained from Test solution 1 is not more intense than the spot obtained from Standard solution 2; and not more than one such spot is more intense than the spot obtained from Standard solution 3.