Flumazenil Injection

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION

Flumazenil Injection is a sterile solution of Flumazenil. It contains NLT 90.0% and NMT 110.0% of the labeled amount of flumazenil (C₁₅H₁₄FN₃O₃).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

B. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

Buffer: 0.02 M monobasic potassium phosphate TS, adjusted with 0.02 M phosphoric acid to a pH of 2.7 ± 0.05

Mobile phase: Tetrahydrofuran, methanol, and Buffer (20:5:75)

Diluent: Tetrahydrofuran, methanol, and water (20:5:75)

System suitability solution: 0.01 mg/mL each of USP Flumazenil RS, USP Flumazenil Related Compound A RS, and USP Flumazenil Related Compound B RS in Diluent

Standard solution: 0.1 mg/mL of USP Flumazenil RS in Mobile phase

Sample solution: Nominally 0.1 mg/mL of flumazenil from Injection prepared as follows. Dilute a portion of Injection with Diluent, if necessary.

3.2 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 230 nm. For Identification B, use a diode array detector in the range of 200-400 nm.

Column: 4.6-mm × 25-cm; 5-µm packing L10

Flow rate: 1 mL/min

Injection volume: 20 µL

Run time: NLT 2 times the retention time of flumazenil

3.3 System suitability

Samples: System suitability solution and Standard solution

[NOTE-See Table 1 for the relative retention times.]

Suitability requirements

Resolution: NLT 1.8 between flumazenil related compound B and flumazenil, System suitability solution

Tailing factor: NMT 2.0 for flumazenil related compound A, System suitability solution

Relative standard deviation: NMT 2.0%, Standard solution

3.4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of flumazenil (C₁₅H₁₄FN₃O₃) in the portion of Injection taken:

Result = (r_U/r_S) x (C_S/C_U) x 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

Acceptance criteria: 90.0%-110.0%

4 IMPURITIES

ORGANIC IMPURITIES

Mobile phase, Diluent, System suitability solution, Standard solution, Sample solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each impurity in the portion of Injection taken:

Result = (r_U/r_S) x (C_S/C_U) x (1/F) x 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

F = relative response factor (see Table 1)

Acceptance criteria: See Table 1.

Table 1

5 SPECIFIC TESTS

5.1 BACTERIAL ENDOTOXINS TEST (85)

NMT 100 USP Endotoxin Units/mg of flumazenil

5.2 PARTICULATE MATTER IN INJECTIONS (788)

Meets the requirements for small-volume injections

5.3 PH (791)

3.4-4.6

5.4 OTHER REQUIREMENTS

Meets the requirements in Injections and Implanted Drug Products (1).

6 ADDITIONAL REQUIREMENTS

6.1 PACKAGING AND STORAGE

Preserve in multiple-dose containers, preferably of Type I glass, and store at controlled room temperature.

6.2 USP REFERENCE STANDARDS (11)

USP Endotoxin RS

USP Flumazenil RS

USP Flumazenil Related Compound A RS

8-Fluoro-5-methyl-6-oxo-5,6-dihydro-4H-benzo[f]imidazo[1,5-a][1,4]diazepine-3-carboxylic acid;

Also known as 8-Fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazol-[1,5-a][1,4]benzodiazepine-3-carboxylic acid.

C₁₃H₁₀FN₃O₃ 275.24

USP Flumazenil Related Compound B RS

Ethyl 8-hydroxy-5-methyl-6-oxo-5,6-dihydro-4H-benzo[f]imidazo[1,5-a][1,4]diazepine-3-carboxylate;

Also known as Ethyl 8-hydroxy-5,6-dihydro-5-methyl-6-oxo-4H-imidazol-[1,5-a][1,4]benzodiazepine-3-carboxylate.

C₁₅H₁₅N₃O₄ 301.30