Acetaminophen Oral Suspension
» Acetaminophen Oral Suspension is a suspension of Acetaminophen in a suitable aqueous vehicle. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of acetaminophen (C8H9NO2).
Packaging and storage Preserve in tight containers, and store at controlled room temperature.
USP Reference standards 11
Identification Transfer a volume of Oral Suspension, equivalent to about 240 mg of acetaminophen, to a separator, add 50 mL of ethyl acetate, and shake. Filter the ethyl acetate extract through a funnel containing glass wool and about 10 g of anhydrous sodium sulfate. Collect the filtrate in a beaker, and evaporate on a steam bath to dryness. Dry the residue in vacuum over silica gel: the crystals so obtained respond to Identification test A under Acetaminophen.
Uniformity of dosage units 905
for oral suspension packaged in single-unit containers: meets the requirements.
Deliverable volume 698
for oral suspension packaged in multiple-unit containers: meets the requirements.
Limit of 4-aminophenol
Diluent Prepare a mixture of water, methanol, and formic acid (425:75:2).
Mobile phase Prepare a filtered and degassed mixture of 0.01 M sodium butanesulfonate in Diluent. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard solution Dissolve an accurately weighed quantity of USP 4-Aminophenol RS, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 24 µg per mL.
Test solution Transfer an accurately measured portion of Oral Suspension, equivalent to about 120 mg of acetaminophen, to a 25-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 272-nm detector and a 4.6-mm × 20-cm column that contains 10-µm packing L1. The flow rate is about 2.0 mL per minute. Chromatograph the Standard solution and the Test solution, and record the peak areas as directed for Procedure.
Procedure Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the areas for the major peaks: the peak area of 4-aminophenol obtained from the Test solution is not greater than the corresponding peak area obtained from the Standard solution.
pH 791: between 4.0 and 6.9.
Mobile phase, Standard preparation, and Chromatographic system Proceed as directed in the Assay under Acetaminophen Capsules.
Assay preparation Transfer an accurately measured volume of Oral Suspension, previously well-shaken, equivalent to about 100 mg of acetaminophen, to a 200-mL volumetric flask, add about 100 mL of Mobile phase, and shake by mechanical means for 10 minutes. Dilute with Mobile phase to volume, and mix. Transfer 5.0 mL of this solution to a 250-mL volumetric flask, dilute with Mobile phase to volume, and mix. Pass a portion of this solution through a filter having a 0.5-µm or finer porosity, discarding the first 10 mL of the filtrate. Use the clear filtrate as the Assay preparation.
Procedure Proceed as directed for Procedure in the Assay under Acetaminophen Capsules. Calculate the quantity, in mg, of acetaminophen (C8H9NO2) in each mL of the Oral Suspension taken by the formula:
10,000(C/V)(rU / rS)in which C is the concentration, in mg per mL, of USP Acetaminophen RS in the Standard preparation; V is the volume, in mL, of Oral Suspension taken; and rU and rS are the acetaminophen peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2032Pharmacopeial Forum: Volume No. 30(5) Page 1579