A: Infrared Absorption 197K.

B: Ultraviolet Absorption 197U—

Solution: 10 µg per mL.

Medium: dilute hydrochloric acid (1 in 100).

C: Dissolve 25 mg in a mixture of 3 mL of 2 N nitric acid and 5 mL of alcohol: the solution responds to the tests for Chloride 191.

Mobile phase— Dissolve 1.5 g of sodium 1-heptanesulfonate in 300 mL of water, and mix this solution with 700 mL of acetonitrile. Adjust with 0.1 N sulfuric acid to a pH of 4, filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).

Standard solution— Dissolve an accurately weighed quantity of USP Meclizine Hydrochloride RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 2.5 µg per mL.

Test solution— Prepare a solution of Meclizine Hydrochloride in Mobile phase having a known concentration of about 0.5 mg per mL.

System suitability solution— Prepare a solution in Mobile phase containing about 0.01 mg of USP Meclizine Hydrochloride RS and 0.01 mg of 4-chlorobenzophenone per mL.

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 230-nm detector and a 4.6-mm × 25-cm column that contains 10-µm packing L1. The flow rate is about 1.3 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.8 for meclizine hydrochloride and 1.0 for 4-chlorobenzophenone; and the resolution, R, between the 4-chlorobenzophenone and meclizine hydrochloride peaks is not less than 2.0. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the tailing factor for the analyte peak is not more than 1.5; the column efficiency, N, determined from the analyte peak is not less than 1800 theoretical plates; and the relative standard deviation for replicate injections is not more than 1.5%.

Procedure— Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph. Allow the Test solution to elute for not less than three times the retention time of meclizine hydrochloride. Record the chromatograms and measure all of the peak areas: the sum of the peak responses, excluding that of meclizine hydrochloride, from the Test solution is not more than two times the meclizine hydrochloride response from the Standard solution (1.0%), and no single peak response is greater than that of the meclizine hydrochloride response from the Standard solution (0.5%).

(Official January 1, 2007)