Tetracaine Hydrochloride 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

Tetracaine Hydrochloride Injection is a sterile solution of Tetracaine Hydrochloride in Water for Injection. It contains NLT 95.0% and NMT 105.0% of the labeled amount of tetracaine hydrochloride (C₁₅H₂₄N₂O₂· HCl).

2 IDENTIFICATION

A.

Sample solution: 100 mg in 10 mL of water

Analysis: To the Sample solution add 1 mL of potassium thiocyanate solution (1 in 4). A crystalline precipitate is formed. Recrystallize the precipitate from water, and dry at 80° for 2 h.

Acceptance criteria: The crystalline precipitate melts between 130° and 132°.

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

3 ASSAY

3.1 Procedure

Mobile phase: Acetonitrile, methanol, and water (20:20:60) containing 0.06% of sulfuric acid, 0.5% of sodium sulfate, and 0.02% of sodium 1- heptanesulfonate. The pH is about 2.6.

Diluent: Methanol and water (1:1)

Standard solution: 1 mg/mL of USP Tetracaine Hydrochloride RS in Diluent

System suitability solution: 4 mg/mL of salicylic acid and 1 mg/mL of tetracaine hydrochloride in Standard solution

Sample solution: Nominally 1 mg/mL of tetracaine hydrochloride in Diluent from Injection

3.2 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 305 nm

Column: 3.9-mm × 30-cm; packing L1

Flow rate: 2 mL/min

Injection volume: 5 μL

3.3 System suitability

Samples: System suitability solution and Standard solution

[Note—The relative retention times for salicylic acid and tetracaine are about 0.8 and 1.0, respectively.]

3.4 Suitability requirements

Resolution: NLT 2 between salicylic acid and tetracaine peaks, System suitability solution

Relative standard deviation: NMT 2.0% for replicate injections, Standard solution

3.5 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of tetracaine hydrochloride (C₁₅H₂₄N₂O₂ · HCl) in the portion of Injection taken:

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

r_U = peak response of tetracaine from the Sample solution

r_S = peak response of tetracaine from the Standard solution

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

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

Acceptance criteria: 95.0%–105.0%

4 SPECIFIC TESTS

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

Bacterial Endotoxins Test 〈85〉: NMT 0.7 USP Endotoxin Units/mg of tetracaine hydrochloride

pH 〈791〉: 3.2–6.0

Other Requirements: It meets the requirements in Injections and Implanted Drug Products 〈1〉.

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in single-dose or in multiple-dose containers, preferably of Type I glass, under refrigeration and protected from light. It may be packaged in 100-mL multiple-dose containers. Injection supplied as a component of spinal anesthesia trays may be stored at room temperature for 12 months.

Labeling: Label it to indicate that the Injection is not to be used if it contains crystals, or if it is cloudy or discolored.

USP Reference Standards 〈11〉

USP Tetracaine Hydrochloride RS