Bethanechol Chloride Oral Suspension
Bethanechol Chloride Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of bethanechol chloride (C7H17ClN2O2).
Prepare Bethanechol Chloride Oral Suspension 5 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795).
Bethanechol Chloride 500 mg
Vehicle: a mixture of Vehicle for Oral Solution, (regular or sugar-free), NF and Vehicle for Oral Suspension, NF (1:1), a sufficient quantity to make 100 mL
If using Bethanechol Chloride tablets, add to a suitable mortar and comminute to a fine powder, or add the Bethanechol Chloride powder to the mortar. Add about 20 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 a calibrated bottle. Add sufficient Vehicle to final volume, and mix well.
•  Procedure
Mobile phase:  Acetonitrile and water (33:67)
Standard solution:  500 µg/mL of USP Bethanechol Chloride RS in Mobile phase
Sample solution:  Agitate the container of Oral Suspension for 30 min 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 s. Dilute a suitable volume of Oral Suspension with Mobile phase to obtain a nominal concentration of 500 µg/mL of bethanechol chloride.
Chromatographic system 
Mode:  LC
Detector:  UV 200 nm
Column:  4.6-mm × 25-cm; 5-µm packing L11
Flow rate:  0.7 mL/min
Injection size:  20 µL
System suitability 
Sample:  Standard solution
[Note—The retention time for bethanechol chloride is about 3 min. ]
Suitability requirements 
Relative standard deviation:  NMT 3.1% for replicate injections
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of bethanechol chloride (C7H17ClN2O2) in the volume of Oral Suspension taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response from the Sample solution
rS== peak response from the Standard solution
CS== concentration of bethanechol chloride in the Standard solution (µg/mL)
CU== nominal concentration of bethanechol chloride in the Sample solution (µg/mL)
Acceptance criteria:  90.0%–110.0%
•  pH 791: 3.9–4.9
•  Packaging and Storage: Package 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, and to state the Beyond-Use Date.
•  Beyond-Use Date: NMT 60 days after the day on which it was compounded.
•  USP Reference Standards 11
USP Bethanechol Chloride RS Click to View Structure
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
(CMP2010) Compounding
Reference Standards RS Technical Services
USP35–NF30 Page 2352
Pharmacopeial Forum: Volume No. 32(1) Page 57