Phenoxybenzamine Hydrochloride Compounded Oral Suspension
DEFINITION
Phenoxybenzamine Hydrochloride Compounded Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of phenoxybenzamine hydrochloride (C18H22ClNO·HCl).
Prepare Phenoxybenzamine Hydrochloride Compounded Oral Suspension 10 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 
795
).
795).| Phenoxybenzamine Hydrochloride powder
|
1 g |
| Corn Oil, NF, a sufficient quantity to make | 100 mL |
Pour the weighed Phenoxybenzamine Hydrochloride powder into a suitable mortar. Wet the powder with a small amount of Corn Oil, and triturate to make a smooth paste. Add the Corn Oil to make the mortar contents pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated container using the Corn Oil to rinse the mortar. Add sufficient Corn Oil to bring the preparation to final volume. Shake to mix well.
ASSAY
• Procedure
Solution A:
25 mM monobasic potassium phosphate adjusted with phosphoric acid to a pH of 3.1
Mobile phase:
Acetonitrile and Solution A (70:30)
Diluent:
Prepare a mixture of 20 mL of acetonitrile and 80 mL of isopropyl alcohol in a conical flask. Add 10 g of anhydrous sodium sulfate to the flask, shake well for 1 min, and allow the sodium sulfate to precipitate to the bottom. [Note—The addition of anhydrous sodium sulfate removes trace amounts of water in the solvent. ]
Standard solution:
0.5 mg/mL of phenoxybenzamine hydrochloride prepared from USP Phenoxybenzamine Hydrochloride RS in acetonitrile
Sample solution:
Shake thoroughly each bottle of Oral Suspension. Transfer 0.5 mL of the Oral Suspension into a 10-mL volumetric flask, dilute with Diluent to volume, and mix well to dissolve.
Chromatographic system
Mode:
LC
Detector:
UV 220 nm
Column:
3.9-mm × 15-cm; 5-µm packing L1
Flow rate:
1.5 mL/min
Injection volume:
10 µL
System suitability
Sample:
Standard solution
[Note—The retention time for phenoxybenzamine hydrochloride is about 5.2 min. ]
Suitability requirements
Tailing factor:
NMT 2.0
Relative standard deviation:
NMT 2.0% for replicate injections
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of the labeled amount of phenoxybenzamine hydrochloride (C18H22ClNO·HCl) in the portion of Oral Suspension taken:
Result = (rU/rS) × (CS/CU) × 100
| rU | = | = peak response of phenoxybenzamine hydrochloride from the Sample solution |
| rS | = | = peak response of phenoxybenzamine hydrochloride from the Standard solution |
| CS | = | = concentration of phenoxybenzamine hydrochloride in the Standard solution (mg/mL) |
| CU | = | = nominal concentration of phenoxybenzamine hydrochloride in the Sample solution (mg/mL) |
Acceptance criteria:
90.0%–110.0%
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Package in tight, light-resistant containers. Store at 2
–8 or at controlled room temperature.
–8 or at controlled room temperature.
• Beyond-Use Date:
NMT 90 days after the date on which it was compounded when stored at 2–8 or controlled room temperature
–8 or controlled room temperature
• Labeling:
Label it to indicate that it is to be well-shaken immediately before use, and to state the Beyond-Use Date.
• USP Reference Standards 11
11
USP Phenoxybenzamine Hydrochloride RS 
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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, Pharm.D.
Associate Scientific Liaison (301) 230-3361 |
(CMP2010) Compounding |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP38–NF33 Page 4843
Pharmacopeial Forum: Volume No. 39(4)