Quinidine Sulfate Oral Suspension
» Quinidine Sulfate Oral Suspension contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of quinidine sulfate [(C20H24N2 O2)2 ·H2SO4·2H2O]. Prepare Quinidine Sulfate Oral Suspension 10 mg per mL as follows (see Pharmaceutical CompoundingNonsterile Preparations 795):
If using Quinidine Sulfate Tablets, place in a suitable mortar, and comminute into a fine powder, or add Quinidine Sulfate powder to the mortar. Add about 15 mL of the Vehicle, and mix to a uniform paste. Add the Vehicle in small portions almost to volume, and mix thoroughly after each addition. Transfer the contents of the mortar, stepwise and quantitatively, to the calibrated bottle. Add sufficient Vehicle to volume, and mix well.
Packaging and storage Preserve in tight, light-resistant containers. Store at room temperature, or in a cold place.
Labeling Label it to state that it is to be well shaken before use, and to state the beyond-use date.
USP Reference standards 11
USP Quinindine Sulfate RS.
pH 791: between 3.4 and 4.4.
Beyond-use date: 60 days after the day on which it was compounded.
Methanesulfonic acid solution Add 35.0 mL of methanesulfonic acid to 20.0 mL of glacial acetic acid, dilute with water to 500 mL, and mix.
Diethylamine solution Dissolve 10.0 mL of diethylamine in water to obtain 100 mL of solution.
Mobile phase Prepare a suitable filtered and degassed solution of water, acetonitrile, Methanesulfonic acid solution, and Diethylamine solution (80:20:2:2). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation Dissolve USP Quinidine Sulfate RS in Mobile phase to obtain a solution having a known concentration of about 100 µg per mL.
Assay preparation Agitate the container of Oral Suspension for 30 minutes on a rotating mixer, remove a 5-mL sample, and store in a clear glass vial at 70 until analyzed. At the time of analysis, remove the sample from the freezer, allow it to reach room temperature, and mix on a vortex mixer for 30 seconds. Pipet 1.0 mL of the sample solution into a 100-mL volumetric flask, and dilute with Mobile phase to volume.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 235-nm detector and a 4.6-mm × 25-cm analytical column that contains 5-µm packing L1. The flow rate is about 1.0 mL per minute. Chromatograph the 100 µg per mL Standard preparation, and record the peak responses as directed for Procedure: the retention time for quinidine sulfate is about 8.5 minutes, and the relative standard deviation for replicate injections is not more than 1.0%.
Procedure Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of quinidine sulfate [(C20 H24 N2 O2)2·H2SO4·2H2O] in the volume of Oral Suspension taken by the formula:
100(C / V)(rU / rS)in which C is the concentration, in µg per mL, of USP Quinidine Sulfate RS in the Standard preparation; V is the volume, in mL, of Oral Suspension taken; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP32NF27 Page 3465Pharmacopeial Forum: Volume No. 32(1) Page 136