Alfentanil Injection

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

Alfentanil Injection is a sterile solution of Alfentanil Hydrochloride in Water for Injection. It contains an amount of Alfentanil Hydrochloride equivalent to NLT 90.0% and NMT 110.0% of the labeled amount of alfentanil (C₂₁H₃₂N₆O₃).

[Caution—Handle Alfentanil Injection with great care because it is a potent opioid analgesic.]

2 IDENTIFICATION

A. Thin-Layer Chromatographic Identification Test 〈201〉

Standard solution: 0.54 mg/mL of USP Alfentanil Hydrochloride RS

Sample solution: 0.5 mg/mL of alfentanil in water

2.1 Chromatographic system

Application volume: 200 µL

Developing solvent system: Chloroform, methanol, and formic acid (85:10:5)

Visualizing agent: Dragendorff's reagent

2.2 Analysis

Samples: Standard solution and Sample solution

Proceed as directed in the chapter.

Acceptance criteria: Meets the requirements

B. The retention time 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

Mobile phase: Acetonitrile and 0.01 M tetrabutylammonium hydrogen sulfate (14:86)

Standard solution: 0.54 mg/mL of USP Alfentanil Hydrochloride RS in saline TS

Sample solution: Equivalent to 0.50 mg/mL of alfentanil from a suitable volume of Injection in saline TS Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 235 nm

Column: 4.6-mm × 25-cm; 5-µm packing L1

Flow rate: 2 mL/min

Injection volume: 25 µL

System suitability

Sample: Standard solution

Suitability requirements

Column eciency: NLT 5400 theoretical plates

Tailing factor: NMT 1.3

Relative standard deviation: NMT 1.0%

3.2 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of alfentanil (C₂₁H₃₂N₆O₃ ) in the portion of Injection taken:

Result = (r_U /r_S ) × (C_S /C_U ) × (M_r1 /M_r2 ) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

M_r1 = molecular weight of alfentanil, 416.52

M_r2 = molecular weight of alfentanil hydrochloride, 452.98

Acceptance criteria: 90.0%–110.0%

4 IMPURITIES

4.1 Organic Impurities

Mobile phase: Acetonitrile and 0.01 M tetrabutylammonium hydrogen sulfate (14:86)

Standard solution: 0.54 mg/mL of USP Alfentanil Hydrochloride RS in saline TS

Sample solution: Equivalent to 0.50 mg/mL of alfentanil from a suitable volume of Injection in saline TS

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 235 nm

Column: 4.6-mm × 25-cm; 5-µm packing L1

Flow rate: 2 mL/min

Injection volume: 25 µL

System suitability

Sample: Standard solution

Suitability requirements

Column eciency: NLT 5400 theoretical plates

Tailing factor: NMT 1.3

Relative standard deviation: NMT 1.0%

4.2 Analysis

Sample: Sample solution

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

Result = (r_U /r_T ) × 100

r_U = peak response of each impurity

r_T = sum of all of the peaks

Acceptance criteria: The sum of all impurities is NMT 2.0%.

5 SPECIFIC TESTS

pH 〈791〉: 4.0–6.0

Particulate Matter in Injections 〈788〉: Meets the requirements for small-volume injections

Bacterial Endotoxins Test 〈85〉: NMT 10 USP Endotoxin Units/mL

Other Requirements: Meets the requirements in Injections and Implanted Drug Products 〈1〉

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, single-dose or multiple-dose containers, preferably of Type I glass, and store at controlled room temperature.

USP Reference Standards 〈11〉

USP Alfentanil Hydrochloride RS.