Dapsone Compounded Oral Suspension

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
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1 DEFINITION

Dapsone Compounded Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of dapsone (C₁₂H₁₂N₂O₂S).

Prepare Dapsone Compounded Oral Suspension 2 mg/mL as follows (see Pharmaceutical Compounding-Nonsterile Preparations (795)).

a Dapsone 25-mg tablets, Jacobus Pharmaceutical Company, Princeton, NJ.

b Paddock Laboratories, Minneapolis, MN.

Calculate the required quantity of each ingredient for the total amount to be prepared. Place the required number of Dapsone tablets in a suitable mortar, and comminute to a fine powder. Add the Vehicle in small portions, and triturate to make a smooth paste. Add increasing volumes of the Vehicle to make a dapsone liquid that is pourable. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough of the Vehicle to bring to final volume, and mix well.

1.1 ASSAY

1.2 PROCEDURE

Solution A: 50 mM ammonium phosphate adjusted to a pH of 4.6

Mobile phase: Acetonitrile and Solution A (12:88). Filter and degas.

Internal standard solution: 1.0 mg/mL of diazoxide in methanol

Standard stock solution: 2.0 mg/mL of USP Dapsone RS in methanol

Standard solution: Pipet 2.5 mL of Standard stock solution into a 100-mL volumetric flask, add 5.0 mL of Internal standard solution, and dilute with Mobile phase to volume to obtain a solution with a nominal concentration of 50 µg/mL of dapsone and 50 µg/mL of diazoxide. Centrifuge.

Sample solution: Shake thoroughly by hand each bottle of Oral Suspension. Pipet 2.5 mL of Oral Suspension into a 100-mL volumetric flask, add 5.0 mL of Internal standard solution, and dilute with Mobile phase to volume to obtain a solution with a nominal concentration of 50 µg/mL of dapsone and 50 µg/mL of diazoxide. Centrifuge.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 295 nm

Column: 3 - mm * 15 - cm 5-µm packing L1

Column temperature: 40°

Flow rate: 0.7 mL/min

Injection volume: 10 µL

System suitability

Sample: Standard solution

[NOTE-The retention times for dapsone and diazoxide are about 8.9 and 12.9 min, respectively.]

Suitability requirements

Relative standard deviation: NMT 2.3% for replicate injections

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of dapsone (C₁₂H₁₂N₂O₂S) in the portion of Oral Suspension taken:

Result = (R_u/R_s) × (C_s/C_u) × 100

R_u = peak response ratio of dapsone to the internal standard from the Sample solution

R_s = peak response ratio of dapsone to the internal standard from the Standard solution 

C_s = concentration of USP Dapsone RS in the Standard solution (µg/mL)

C_u = nominal concentration of dapsone in the Sample solution (µg/mL)

Acceptance criteria: 90.0%-110.0%

2 SPECIFIC TESTS

2.1 PH (791): 3.8-4.8

3 ADDITIONAL REQUIREMENTS

3.1 PACKAGING AND STORAGE:

Package in tight, light-resistant containers. Store in a refrigerator or at controlled room temperature.

3.2 BEYOND-USE DATE:

NMT 90 days after the date on which it was compounded when stored in a refrigerator or at controlled room temperature

3.3 LABELING:

Label it to indicate that it is to be well shaken before use, and to state the Beyond-Use Date.

3.4 USP REFERENCE STANDARDS (11)

USP Dapsone RS