Dolasetron Mesylate Oral Suspension
» Dolasetron Mesylate Oral Suspension contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of dolasetron mesylate (C19H20N2O3·CH4O3S). Prepare Dolasetron Mesylate Oral Suspension 10 mg per mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795. See also Dolasetron Mesylate Oral Solution):
Dolasetron Mesylate 1 g
Vehicle: a mixture of Vehicle for Oral Suspension, NF, and Vehicle for Oral Solution, (regular or sugar-free), NF (1:1), a sufficient  
quantity to make 100 mL
If using Tablets, place the Dolasetron Mesylate Tablets in a suitable mortar, and comminute to a fine powder, or add Dolasetron Mesylate powder to the mortar. Add about 20 mL of Vehicle, and mix to a uniform paste. Add the Vehicle in small portions, and mix well after each addition. Transfer, stepwise and quantitatively, to a calibrated bottle. Add the Vehicle in portions to rinse the mortar, add sufficient Vehicle to bring to final volume, and mix well.
Packaging and storage— Preserve in tight, light-resistant containers. Store at controlled 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 Dolasetron Mesylate RS Click to View Structure
pH 791: between 3.6 and 4.6.
Beyond-use date: 90 days after the day on which it was compounded.
Buffer— Prepare a solution of 0.05 M ammonium acetate adjusted with diluted ammonium hydroxide to a pH of 7.5.
Mobile phase— Prepare a filtered and degassed solution of Buffer and acetonitrile (76:24). Make adjustments if necessary (see System Suitability under Chromatography 621).
Sample diluent— Prepare a solution of water and acetonitrile (76:24).
Standard stock preparation— Dissolve an accurately weighed quantity of USP Dolasetron Mesylate RS in Sample diluent to obtain a solution having a known concentration of about 500 µg per mL.
Standard preparation— Transfer 2 mL of Standard stock preparation to a 100-mL volumetric flask, and dilute with Mobile phase to volume to obtain a solution having a known concentration of about 10 µg per mL.
Assay preparation— Transfer 1.0 mL of Oral Suspension by pipet to a 100-mL volumetric flask, and dilute with Sample diluent to obtain a 10 µg per mL concentration. Shake each sample thoroughly by hand for about 15 seconds, centrifuge at 1000 rpm for about 2 minutes, and assay the supernatant.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 280-nm detector and a 4.6-mm × 15-cm analytical column that contains 5-µm packing L10, and is maintained at a temperature of 30. The flow rate is about 0.8 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the retention time is about 6.9 minutes, and the relative standard deviation for replicate injections is not more than 1.4%.
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 responses for the major peaks. Calculate the quantity, in mg, of dolasetron mesylate (C19H20N2O3·CH4O3S) in the volume of Oral Suspension taken by the formula:
1000(C/V)(rU / rS)
in which C is the concentration, in µg per mL, of USP Dolasetron Mesylate 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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Monograph Jeanne H. Sun
Assistant Scientific Liaison
(CMP2010) Compounding
Reference Standards RS Technical Services
USP35–NF30 Page 2965
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