Labetalol Hydrochloride Tablets
»Labetalol Hydrochloride Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of labetalol hydrochloride (C19H24N2O3·HCl).
Packaging and storage— Preserve in tight,light-resistant containers,at a temperature between 2and 30.
Identification— The retention time of the major peak in the chromatogram of the Assay preparationcorresponds to that of the Standard preparation,as obtained in the Assay.
Dissolution á711ñ
Medium: water;900mL.
Apparatus 2: 50rpm.
Time: 45minutes.
Procedure— Determine the amount of C19H24N2O3·HCl dissolved from UVabsorbances at the wavelength of maximum absorbance at about 302nm of filtered portions of the solution under test,suitably diluted with water,if necessary,in comparison with a Standard solution having a known concentration of USP Labetalol Hydrochloride RSin the same Medium.
Tolerances— Not less than 80%(Q)of the labeled amount of C19H24N2O3·HCl is dissolved in 45minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Mobile phase ,Standard preparation,and Chromatographic system—Proceed as directed in the Assayunder Labetalol Hydrochloride.
Assay preparation— Transfer an accurately counted number of Tablets,equivalent to about 2000mg of labetalol hydrochloride,to a 500-mLvolumetric flask,add 200mLof water,and shake by mechanical means for 60minutes.Dilute with water to volume,and mix.Filter the solution through a filter of 0.5µm or finer porosity,discarding the first few mLof the filtrate.Transfer 10.0mLof the filtrate to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.
Procedure— Separately inject equal volumes (about 5µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the area responses for the major peaks.Calculate the quantity,in mg,of labetalol hydrochloride (C19H24N2O3·HCl)in each Tablet taken by the formula:
in which Cis the concentration,in mg per mL,of USP Labetalol Hydrochloride RSin the Standard preparation;Nis the number of Tablets taken;and rUand rSare the peak area responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1104
Phone Number:1-301-816-8305