Terbutaline Oral Suspension
Terbutaline Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled content of terbutaline sulfate [(C12H19NO3)2·H2SO4]. Prepare Terbutaline Oral Suspension (1 mg/mL) as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795).
Terbutaline Sulfate 100 mg
Syrup, NF,a a sufficient quantity to make 100 mL
a  Syrup, NF, containing 0.2% sodium benzoate.
Calculate the required quantity of each ingredient for the total amount to be prepared. If using tablets, place the required number of tablets in a suitable mortar, and comminute the tablets to a fine powder or add Terbutaline Sulfate powder. Add the Syrup, NF, to make a terbutaline suspension that is pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough of the Syrup, NF, to bring to final volume, and mix well.
•  Procedure
Mobile phase:  A solution of methanol and 20 mM monobasic potassium phosphate (2:23), adjusted with phosphoric acid to a pH of 3.6. Filter and degas.
Standard stock solution:  5 mg/mL of USP Terbutaline Sulfate RS in methanol
Standard solution:  Transfer 0.2 mL of Standard stock solution to a 100-mL volumetric flask, dilute with water to volume to obtain a solution containing 10 µg/mL of terbutaline sulfate, and pass through a suitable filter of 0.22-µm pore size.
Sample solution:  Shake thoroughly by hand each bottle of Oral Suspension. Accurately pipet 1.0 mL to a 10-mL volumetric flask. Dilute with Mobile phase to volume to obtain a nominal concentration of 100 µg/mL of terbutaline sulfate. Extract terbutaline sulfate from the suspension with methanol. Accurately pipet 1 mL of Oral Suspension and 3 mL of Mobile phase in the barrel of a 5-mL plastic syringe. Shake, and pass through a suitable filter of 0.22-µm pore size into a 10-mL volumetric flask. Repeat the process with an additional 2 mL of methanol. Bring to a final volume of 10 mL with Mobile phase to obtain a nominal concentration of 10 µg/mL of terbutaline sulfate.
Chromatographic system 
Mode:  LC
Detector:  UV 278 nm
Column:  3.9-mm × 30-cm; 10-µm microphenyl packing L11
Flow rate:  2 mL/min
Injection size:  20 µL
System suitability 
Sample:  Standard solution
[Note—The retention time for the terbutaline peak is 5 min. ]
Suitability requirements 
Relative standard deviation:  NMT 2.2% for replicate injections
Samples:  Standard solution and Sample solution
Calculate the percentage of the labeled amount of (C12H19NO3)2·H2SO4 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 terbutaline sulfate in the Standard solution (µg/mL)
CU== nominal concentration of terbutaline sulfate in the Sample solution (µg/mL)
Acceptance criteria:  90.0%–110.0%
•  Packaging and Storage: Package in tight, light-resistant containers. Store at controlled cold temperature.
•  Labeling: Label it to state that it is to be well shaken before use, and to state the Beyond-Use Date.
•  Beyond-Use Date: NMT 30 days after the date on which it was compounded when stored at controlled cold temperature
•  USP Reference Standards 11
USP Terbutaline Sulfate 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 4792
Pharmacopeial Forum: Volume No. 35(1) Page 97