Packaging and storage—
Preserve in tight containers.
Identification—
Transfer a quantity of powdered Tablets, equivalent to about 30 mg of Praziquantel, to a centrifuge tube, add 5 mL of methanol, agitate for 5 minutes, and centrifuge. Use the clear supernatant as the test solution. Apply separately, as 1-cm wide bands, 10 µL each of the test solution and a Standard solution of
USP Praziquantel RS in methanol containing 6 mg per mL to a thin-layer chromatographic plate (see
Chromatography 
621
) coated with a 0.25-mm layer of chromatographic silica gel mixture. Develop the chromatogram in an unsaturated chamber, using ethyl acetate as the developing solvent, until the solvent front has moved about 8 cm. Remove the plate from the chamber, air-dry, and examine under short-wavelength UV light: the
RF value of the principal band in the chromatogram of the test solution corresponds to that obtained for the Standard solution.
Dissolution 711—
Medium:
0.1 N hydrochloric acid containing 2.0 mg of sodium lauryl sulfate per mL; 900 mL.
Apparatus 2:
50 rpm.
Time:
60 minutes.
Standard preparation—
Dissolve an accurately weighed quantity of
USP Praziquantel RS in methanol to obtain a solution having a known concentration of about
L/90 mg per mL,
L being the labeled quantity, in mg, of praziquantel in each Tablet. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with
Dissolution Medium to volume, and mix.
Procedure—
Determine the amount of C19H24N2O2 dissolved from UV absorbances at the wavelength of maximum absorbance at about 263 nm of filtered portions of the solution under test in comparison with the Standard preparation.
Tolerances—
Not less than 75% (Q) of the labeled amount of C19H24N2O2 is dissolved in 60 minutes.
Assay—
Mobile phase and Chromatographic system—
Proceed as directed in the
Assay under
Praziquantel.
Standard preparation—
Dissolve an accurately weighed quantity of
USP Praziquantel RS in
Mobile phase, and dilute quantitatively, and stepwise if necessary, with
Mobile phase to obtain a solution having a known concentration of about 0.18 mg per mL.
Assay preparation—
Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 150 mg of praziquantel, to a 100-mL volumetric flask, add 70 mL of Mobile phase, sonicate for 5 minutes, dilute with Mobile phase to volume, mix, and filter. Transfer 3.0 mL of the filtrate to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Praziquantel. Calculate the quantity, in mg, of C
19H
24N
2O
2 in the portion of Tablets taken by the formula:
2500(C / 3)(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Praziquantel RS in the
Standard preparation, and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
