Identification—
Triturate a quantity of finely powdered Tablets, equivalent to about 100 mg of hydroxyzine hydrochloride, with 50 mL of methanol, and filter. Apply 100 µL of this solution and 100 µL of a solution in the same medium containing 2 mg of
USP Hydroxyzine Hydrochloride RS per mL to a suitable thin-layer chromatographic plate (see
Chromatography 
621
) coated with a 0.25-mm layer of chromatographic silica gel and dried in air for 30 minutes followed by drying in vacuum at 140
for 30 minutes. Proceed as directed in the
Identification test under
Hydroxyzine Hydrochloride Syrup, beginning with “Allow the spots to dry.”
Dissolution 711—
TEST 1—
Medium:
water, 900 mL.
Apparatus 2:
50 rpm.
Time:
45 minutes.
Procedure—
Determine the amount of C
21H
27ClN
2O
2·2HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 230 nm on filtered portions of the solution under test, suitably diluted with
Medium, if necessary, in comparison with a Standard solution having a known concentration of
USP Hydroxyzine Hydrochloride RS in the same
Medium. Calculate the amount of C
21H
27ClN
2O
2·2HCl dissolved per Tablet.
Tolerances—
Not less than 75% (Q) of the labeled amount of C21H27ClN2O2·2HCl is dissolved in 45 minutes.
TEST 2—
If the product complies with this test, the labeling indicates that it meets USP
Dissolution Test 2.
Medium:
water, 250 mL.
Apparatus 3:
30 dips per minute.
Time:
45 minutes.
Procedure—
Determine the amount of C
21H
27ClN
2O
2·2HCl dissolved by employing UV absorption at the wavelength of maximum absorbance at about 230 nm on filtered portions of the solution under test, suitably diluted with
Medium, if necessary, in comparison with a Standard solution having a known concentration of
USP Hydroxyzine Hydrochloride RS in the same
Medium. Calculate the amount of C
21H
27ClN
2O
2·2HCl dissolved per Tablet.
Tolerances—
Not less than 75% (Q) of the labeled amount of C21H27ClN2O2·2HCl is dissolved in 45 minutes.
(Official April 1, 2006)
Assay—
Mobile phase—
Dissolve 6.8 g of monobasic potassium phosphate in 1000 mL of water, add 1000 mL of methanol, and mix. Pass the solution through a polytef membrane filter having a 5-µm or finer porosity, and degas.
Standard preparation—
Dissolve a suitable quantity of
USP Hydroxyzine Hydrochloride RS, accurately weighed, in methanol to obtain a solution having a known concentration of about 100 µg per mL.
Assay preparation—
Place 20 Tablets in a high-speed blender jar containing 400.0 mL of methanol, and blend for 5 minutes. The Tablets are completely disintegrated. Allow to settle, and filter a portion of the supernatant through a polytef membrane filter having a 1-µm or finer porosity. Dilute an accurately measured volume of the filtrate so obtained quantitatively with methanol to obtain an Assay preparation having a concentration of about 100 µg of hydroxyzine hydrochloride per mL.
Chromatographic system (see Chromatography 621)—
The liquid chromatograph is equipped with a 232-nm detector and a 4.6-mm × 25-cm column that contains packing L9. The flow rate is about 2.0 mL per minute. Chromatograph the
Standard preparation, and record the peak responses as directed for
Procedure: the relative standard deviation is not more than 2.5%.
Procedure—
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of hydroxyzine hydrochloride (C
21H
27ClN
2O
2·2HCl) in each Tablet taken by the formula:
(L/D)(C)(rU / rS),
in which
L is the labeled quantity, in mg, of hydroxyzine hydrochloride in each Tablet;
D is the concentration, in µg per mL, of hydroxyzine hydrochloride in the
Assay preparation on the basis of the labeled quantity in each Tablet and the extent of dilution;
C is the concentration, in µg per mL, of
USP Hydroxyzine Hydrochloride RS in the
Standard preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.
