Bethanechol Chloride Oral Solution
» Bethanechol Chloride Oral Solution contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of bethanechol chloride (C7H17ClN2O2). Prepare Bethanechol Chloride Oral Solution 5 mg per mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795. See also Bethanechol Chloride Oral Suspension):
Bethanechol Chloride 500 mg
Vehicle for Oral Solution (regular or
sugar-free), NF, a sufficient quantity
to make 100 mL
Add Bethanechol Chloride powder and about 20 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 well.
Packaging and storage— Preserve in tight, light-resistant containers. Store at room temperature or in a cold place.
Labeling— Label it to state the beyond-use date.
pH 791: between 3.9 and 4.9.
Beyond-use date: 60 days after the day on which it was compounded.
Mobile phase— Prepare a filtered and degassed solution of water and acetonitrile (67:33). Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation— Dissolve an accurately weighed quantity of USP Bethanechol Chloride RS in Mobile phase, and dilute quantitatively with Mobile phase to obtain a solution having a known concentration of about 500 µg per mL.
Assay preparation— Agitate the container of Oral Solution for 30 minutes on a rotating mixer, remove a 10-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 with a vortex mixer for 30 seconds. Pipet 2.0 mL of the sample into a 20-mL volumetric flask, and dilute with Mobile phase to volume.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 200-nm detector and a 4.6-mm × 25-cm analytical column that contains 5-µm packing L11. The flow rate is about 0.7 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the retention time is about 3 minutes, and the relative standard deviation for replicate injections is not more than 3.1%.
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 bethanechol chloride (C7H17ClN2O2) in the volume of Oral Solution taken by the formula:
10(C / V)(rU / rS)
in which C is the concentration, in µg per mL, of USP Bethanechol Chloride 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 Rick G. Schnatz
Manager, Compounding Pharmacy Expert Committee
(CRX05) Compounding Pharmacy05
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 1671
Pharmacopeial Forum: Volume No. 32(1) Page 55