Labetalol Hydrochloride Injection
» Labetalol Hydrochloride Injection is a sterile solution of Labetalol Hydrochloride in Water for Injection. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of labetalol hydrochloride (C19H24N2O3·HCl).
Packaging and storage Preserve in single-dose containers, or in multiple-dose containers not exceeding 60 mL in volume, preferably of Type I glass, at a temperature between 2 and 30. Avoid freezing and exposure to light.
USP Reference standards 11
USP Endotoxin RS
Identification The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that of the Standard preparation, as obtained in the Assay.
Bacterial endotoxins 85 It contains not more than 1.2 USP Endotoxin Units per mg of labetalol hydrochloride.
pH 791: between 3.0 and 4.5.
Other requirements It meets the requirements under Injections 1.
Mobile phase Prepare a suitable filtered and degassed mixture of 0.1 M monobasic sodium phosphate and methanol (65:35). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation Dissolve an accurately weighed quantity of USP Labetalol Hydrochloride RS in Mobile phase to obtain a solution having a known concentration of about 0.5 mg per mL.
Resolution solution Dissolve a quantity of methylparaben in the Standard preparation to obtain a solution containing about 0.08 mg per mL.
Assay preparation Transfer an accurately measured volume of Injection, equivalent to about 50 mg of labetalol hydrochloride, to a 100-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621)The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 20-cm column that contains packing L1 and is maintained at 60 ± 1. The flow rate is about 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the column efficiency determined from the analyte peak is not less than 700 theoretical plates; the tailing factor for the analyte peak is not more than 2.0; and the relative standard deviation for replicate injections is not more than 1.5%. Chromatograph the Resolution solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.6 for methylparaben and 1.0 for labetalol; and the resolution, R, between the methylparaben and labetalol is not less than 2.0.
Procedure Separately inject equal volumes (about 5 µL) of the Standard preparation and the Assay preparation into 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 mL of the Injection taken by the formula:
100(C / V)(rU / rS)in which C is the concentration, in mg per mL, of USP Labetalol Hydrochloride RS in the Standard preparation; V is the volume, in mL, of Injection taken; and rU and rS are the peak area responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 3628