Standard solutions
Dissolve an accurately weighed quantity of
USP Ranitidine Hydrochloride RS in methanol, and dilute with methanol to obtain
Standard solution A, having a known concentration of about 0.22 mg per mL. Dilute portions of
Standard solution A quantitatively with methanol to obtain
Standard solutions B,
C, and
D, having concentrations of 110, 66, and 11 µg per mL, respectively.
Procedure
Separately apply 10 µL each of the
Test solution, each of the
Standard solutions, and the
Identification solution to a thin-layer chromatographic plate (see
Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel mixture. Separately apply an additional 10 µL of the
Test solution to the same plate, and on top of this application, apply 10 µL of the
Resolution solution. Allow the spots to dry, and develop the chromatograms in a solvent system consisting of a mixture of ethyl acetate, isopropyl alcohol, ammonium hydroxide, and water (25:15:5:1) until the solvent front has moved not less than 15 cm from the origin. Remove the plate from the developing chamber, mark the solvent front, and allow to air-dry. Expose the plate to iodine vapors in a closed chamber until the chromatogram is fully revealed. Examine the plate, and compare the intensities of any secondary spots observed in the chromatogram of the
Test solution with those of the principal spots in the chromatograms of
Standard solutions A,
B,
C, and
D, and the
Identification solution: the system suitability requirements are met if there is complete resolution between the primary spots in the chromatogram of the combined
Test solution and
Resolution solution, and if a spot is observed in the chromatogram of
Standard solution D. Any spot observed in the chromatogram of the
Test solution at the
RF value corresponding to that of the principal spot produced by the
Identification solution is not greater in size or intensity than the principal spot obtained from
Standard solution B, corresponding to not more than 0.5%; and no other spot in the chromatogram of the
Test solution exceeds the size or intensity of the principal spot obtained from
Standard solution C (0.3%). The sum of the intensities of all secondary spots obtained from the
Test solution corresponds to not more than 1.0%.