Theophylline Oral Suspension
DEFINITION
Theophylline Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled content of theophylline (C7H8N4O2).
Prepare Theophylline Oral Suspension 5 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 
795
):
795):| Theophylline | 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 |
Calculate the required quantity of each ingredient for the total amount to be prepared. Calculate the amount of Theophylline on the anhydrous basis. If using tablets, place the required number in a suitable mortar, and comminute to a fine powder, or use Theophylline Powder. Add about 20 mL of the Vehicle in small portions, and triturate to make a smooth paste. Add increasing volumes of the Vehicle to make a liquid that is pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated container. Add enough of the liquid Vehicle to bring to final volume, and mix well.
ASSAY
• Procedure
Solution A:
Solution A was prepared by dissolving 2.500 g of sodium citrate and 1.633 g of citric acid (anhydrous) in 850 mL of ASTM Type I water, followed by addition of 150 mL methanol, then filtered using 0.45 µm membrane filters.
Solution B:
Acetonitrile
Mobile phase:
See the gradient table below. Make adjustments, if necessary.
| Time (min) |
Solution A (%) |
Solution B (%) |
|---|---|---|
| 0.0 | 100 | 0.0 |
| 20.0 | 100 | 0.0 |
| 20.01 | 5.0 | 95.0 |
| 25.0 | 5.0 | 95.0 |
| 25.01 | 100 | 0.0 |
Diluent:
Solution A
System suitability solution:
0.10 mg/mL of USP Theophylline RS and 0.20 mg/mL of USP Caffeine RS in Solution A
Standard solution:
0.10 mg/mL of USP Theophylline RS in Solution A
Sample solution:
0.10 mg/mL of Theophylline Oral Suspension in Solution A
Chromatographic system
Mode:
LC
Detector:
UV 280 nm
Column:
4.6-mm × 25-cm; 5-µm packing L1
Flow rate:
1.5 mL/min
Injection size:
20 µL
System suitability
Sample:
System suitability solution
Suitability requirements
Resolution:
NLT 3.0 between the theophylline and caffeine peaks
Tailing factor:
NMT 1.5 for the theophylline peak
Column efficiency:
NLT 1000 theoretical plates for the theophylline peak
Relative standard deviation:
NMT 2.0% for replicate injections
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of the labeled amount of theophylline (C7H8N4O2) in the portion 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 theophylline in the Standard solution (mg/mL) |
| CU | = | = nominal concentration of theophylline in the Sample solution (mg/mL) |
Acceptance criteria:
90.0%–110.0%
SPECIFIC TESTS
• pH 791:
4.0–5.0
791:
4.0–5.0
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Package in tight, light-resistant containers. Store at controlled room temperature. Do not refrigerate.
• Labeling:
Label to state that it is to be well-shaken before use, protected from light, not to be refrigerated, and to state the Beyond-Use Date.
• Beyond-Use Date:
NMT 90 days after the date on which it was compounded, when stored at controlled room temperature
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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 4827
Pharmacopeial Forum: Volume No. 36(2) Page 432