Hydroxyzine Pamoate Oral Suspension
» Hydroxyzine Pamoate Oral Suspension contains hydroxyzine pamoate (C21H27ClN2O2·C23H16O6) equivalent to not less than 90.0 percent and not more than 110.0 percent of the labeled amount of hydroxyzine hydrochloride (C21H27ClN2O2·2HCl).
Packaging and storage— Preserve in tight, light-resistant containers.
USP Reference standards 11
USP Hydroxyzine Hydrochloride RS Click to View Structure
USP Hydroxyzine Pamoate RS Click to View Structure
Identification— The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Uniformity of dosage units 905
for oral suspension packaged in single-unit containers: meets the requirements.
Deliverable volume 698
for oral suspension packaged in multiple-unit containers: meets the requirements.
pH 791: between 4.5 and 7.0.
Mobile phase— Dissolve 7.0 g of monobasic sodium phosphate in 1000 mL of water, and adjust with phosphoric acid to a pH of 4.4. Pass the solution through a 5-µm porosity polytef membrane filter. Mix 900 mL of the filtrate with 900 mL of methanol, and degas by stirring under vacuum prior to use.
Standard preparation— Dissolve an accurately weighed quantity of USP Hydroxyzine Pamoate RS in methanol to obtain a solution having a known concentration of about 0.18 mg per mL (equivalent to about 0.1 mg of hydroxyzine hydrochloride per mL).
Assay preparation— Transfer an accurately measured volume of Oral Suspension, freshly mixed and free from air bubbles, equivalent to about 25 mg of hydroxyzine hydrochloride, to a 250-mL volumetric flask. Dissolve in and dilute with methanol to volume, and mix. Pass this solution through a polytef membrane filter having a 1-µm or finer porosity.
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 2.5 mL per minute. Chromatograph four replicate injections of the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation is not more than 2.0%.
Procedure— Separately inject equal volumes (about 25 µL) of the Standard preparation and the Assay preparation in to the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the equivalent quantity, in percentage, of hydroxyzine hydrochloride (C21H27ClN2O2·2HCl) in the portion of the Oral Suspension taken by the formula:
100(447.83 / 763.27)(CS / CU)(rU / rS)
in which 447.83 and 763.27 are the molecular weights of hydroxyzine hydrochloride and hydroxyzine pamoate, respectively; CS is the concentration, in mg per mL, of USP Hydroxyzine Pamoate RS in the Standard preparation; CU is the concentration, in mg per mL, of hydroxyzine pamoate in the Assay preparation; and rU and rS are the peak responses of the hydroxyzine peak obtained from the Assay preparation and the Standard preparation, respectively.
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Monograph Ravi Ravichandran, Ph.D.
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