Dolasetron Mesylate Oral Solution
» Dolasetron Mesylate Oral Solution 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 Solution 10 mg per mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795. See also Dolasetron Mesylate Oral Suspension):
Dolasetron Mesylate powder 1 g
Vehicle for Oral Solution (regular
or sugar-free), NF, a sufficient 		 
quantity to make 100 mL
Add Dolasetron Mesylate powder and about 15 mL of Vehicle to a mortar, and mix. 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 a calibrated bottle. Add enough Vehicle to bring to final volume, and mix.
Packaging and storage— Preserve in tight, light-resistant containers. Store at controlled room temperature, or in a cold place.
Labeling— Label it 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.
Assay—
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 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 0.1 mL of Oral Solution by micropipet 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 3-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 Solution 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 Solution taken; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Jeanne H. Sun
Assistant Scientific Liaison
1-301-816-3361		 (CMP2010) Compounding
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 2965
Pharmacopeial Forum: Volume No. 32(1) Page 83