Pyrazinamide 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 

Pyrazinamide Compounded Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of pyrazinamide (C₅H₅N₃O)

Prepare Pyrazinamide Compounded Oral Suspension 10 mg/mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 〈795〉). 

a Pyrazinamide 500-mg tablets, Mikart Inc., Atlanta, GA. 

b Paddock Laboratories, Minneapolis, MN. 

Calculate the required quantity of each ingredient for the total amount to be prepared. Place the required number of Pyrazinamide 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 pyrazinamide 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 nal volume, and mix well. 

2 ASSAY 

Procedure 

Solution A: 10 mM monobasic sodium phosphate, adjusted with phosphoric acid to a pH of 3.5 

Mobile phase: Acetonitrile and Solution A (10:90). Filter and degas. 

Standard stock solution: 1.0 mg/mL of USP Pyrazinamide RS in methanol 

Standard solution: Pipet 1.0 mL of the Standard stock solution into a 10-mL volumetric flask, and dilute with methanol to volume to obtain a solution with a nominal concentration of 0.1 mg/mL of pyrazinamide. 

Sample solution: Shake thoroughly by hand each bottle of Oral Suspension. Pipet 1.0 mL of sample into a 100-mL volumetric ask, and dilute with methanol to volume to obtain a solution having a nominal concentration of 0.1 mg/mL. 

Chromatographic system 

(See Chromatography 〈621〉, System Suitability.) 

Mode: LC 

Detector: UV 215 nm 

Column: 4.6-mm × 25-cm; 5-µm packing L7 

Flow rate: 0.8 mL/min 

Injection volume: 20 µL 

System suitability 

Sample: Standard solution 

[Note—The retention time for pyrazinamide is about 6.5 min.] 

Suitability requirements 

Column efficiency: NLT 8000 theoretical plates 

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 pyrazinamide (C₅H₅N₃O) in the portion of Oral Suspension taken: Result = (r_U/r_S) × (C_S/C_U) × 100 

r_U = peak response from the Sample solution 

r_S = peak response from the Standard solution 

C_S = concentration of USP Pyrazinamide RS in the Standard solution (mg/mL) 

C_U = nominal concentration of pyrazinamide in the Sample solution (mg/mL) 

Acceptance criteria: 90.0%–110.0% 

3 SPECIFIC TESTS 

pH 〈791〉: 3.9–5.0 

4 ADDITIONAL REQUIREMENTS 

Packaging and Storage: Package in tight, light-resistant containers. Store at controlled room temperature or in a refrigerator. Beyond-Use Date: NMT 60 days after the date on which it was compounded, when stored in a refrigerator or at controlled room temperature Labeling: Label it to indicate that it is to be well shaken before use, and to state the Beyond-Use Date. 

USP Reference Standards 〈11〉 

USP Pyrazinamide RS