A:
Transfer a portion of the Cefprozil for Oral Suspension powder, equivalent to about 50 mg of cefprozil, to a 20-mL glass-stoppered test tube, add 10 mL of a mixture of acetone and 0.1 N hydrochloric acid (4:1), shake for 5 minutes, and allow to settle. Use the supernatant as the test solution. Dissolve a suitable quantity of
USP Cefprozil (Z)-Isomer RS in a mixture of acetone and 0.1 N hydrochloric acid (4:1) to obtain a Standard solution containing 5 mg per mL. Apply separate 10-µL portions of the test solution and the Standard solution to a suitable 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 develop the chromatogram in an equilibrated chromatographic chamber with a solvent system consisting of a mixture of butyl alcohol, water, and glacial acetic acid (60:20:20) until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, and allow the plate to air-dry in a hood. Place the dry plate in a chamber containing iodine vapors. Examine the plate, and locate the spots: the
RF value of the principal spot in the chromatogram obtained from the
Test solution corresponds to that obtained from the
Standard solution.