Betaxolol Hydrochloride
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C18H29NO3·HCl 343.89

2-Propanol, 1-4-2-(cyclopropylmethoxy)ethylphenoxy-3-(1-methylethyl)amino-, hydrochloride, (±)-.
(±)-1-p-2-(Cyclopropylmethoxy)ethylphenoxy-3-(isopropylamino)-2-propanol hydrochloride [63659-19-8].
» Betaxolol Hydrochloride contains not less than 98.5 percent and not more than 101.5 percent of C18H29 NO3·HCl, calculated on the dried basis.
Packaging and storage— Preserve in tight containers.
B: It responds to the test for Chloride 191 when tested as directed for alkaloidal hydrochlorides.
Melting range, Class I 741: between 113 and 117.
pH 791: between 4.5 and 6.5, in a solution (1 in 50).
Loss on drying 731 Dry it in vacuum at 65 for 2 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Chromatographic purity—
Buffer— Prepare a solution of 0.025 M monobasic potassium phosphate containing 0.1% (w/v) of tetrabutylammonium bromide. Adjust with 0.025 M phosphoric acid to a pH of 3.0.
Mobile phase— Prepare a suitable filtered and degassed mixture of Buffer and acetonitrile (85:15). Make adjustments if necessary (see System Suitability under Chromatography 621).
Resolution solution— Prepare a solution in Mobile phase containing 2.0 mg of USP Betaxolol Hydrochloride RS and 1 mg of alprenolol hydrochloride per mL.
Test preparation— Prepare a solution of Betaxolol Hydrochloride in Mobile phase containing 2.0 mg per mL.
Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 273-nm detector and a 4.6-mm × 15-cm column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.9 for alprenolol and 1.0 for betaxolol; the resolution, R, between the two peaks is not less than 1.0; the tailing factors for the two peaks are not more than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Inject about 20 µL of the Test preparation into the chromatograph, record the chromatogram, and measure the areas for the peaks. [note—Allow the elution to continue for about five times the elution time of the betaxolol peak before making the next injection.] Calculate the percentage of each impurity by the same formula:
100(ri / rS)
in which ri is the response of each individual peak, other than the main betaxolol peak, in the chromatogram obtained from the Test preparation, and rS is the sum of the responses of all the peaks obtained in the chromatogram from the Test preparation: the sum of all impurities found is not more than 1.0%.
Assay— Dissolve about 300 mg of Betaxolol Hydrochloride, accurately weighed, in 50 mL of glacial acetic acid. Add 7 mL of mercuric acetate TS, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 34.39 mg of C18H29NO3·HCl.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Feiwen Mao, M.S.
(MDOOD05) Monograph Development-Ophthalmics Oncologics and Dermatologicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1667
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.