Tetracaine
[CAS# 94-24-6]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridazine
• Name: Tetracaine
• Synonyms: 4-(Butylamino)benzoic acid 2-(dimethylamino)ethyl ester
• Molecular Formula: C₁₅H₂₄N₂O₂
• Molecular Weight: 264.37
• CAS Registry Number: 94-24-6
• EC Number: 202-316-6
• SMILES: CCCCNC1=CC=C(C=C1)C(=O)OCCN(C)C

Properties

• Density: 1.0$+/-$0.1 g/cm³ Calc.^*
• Melting point: 43 $degree$C (Expl.)
• Boiling point: 389.4$+/-$27.0 $degree$C 760 mmHg (Calc.)^*
• Flash point: 189.3$+/-$23.7 $degree$C (Calc.)^*
• Solubility: DMSO:44mg/mL (Expl.)
• Index of refraction: 1.538 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08 Danger
• Risk Statements: H301-H317-H351
• Safety Statements: P203-P261-P264-P270-P272-P280-P301+P316-P302+P352-P318-P321-P330-P333+P317-P362+P364-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Carcinogenicity	Carc.	2	H351
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 2811

Discovery and Applications

Tetracaine is an aromatic amino ester compound widely used as a local anesthetic. Chemically, it belongs to the ester-type anesthetics and is structurally characterized by an ester linkage connecting a substituted benzoic acid moiety to a diethylaminoethyl group. Its chemical name is 2-(Dimethylamino)ethyl 4-(butylamino)benzoate. Tetracaine is colorless to pale yellow and is practically insoluble in water but soluble in alcohol and other organic solvents.

The molecular structure of tetracaine features a benzene ring substituted with an amino group at the para position and an ester linkage to a dimethylaminoethyl chain. This combination allows the molecule to interact with voltage-gated sodium channels in nerve membranes. The lipophilic aromatic portion facilitates penetration into neuronal membranes, while the amino group contributes to water solubility and receptor interaction.

Tetracaine was first synthesized in the early 20th century as part of the development of synthetic local anesthetics to replace cocaine, providing similar anesthetic effects without the addictive properties. Its potent and long-lasting action made it a widely used anesthetic for surface anesthesia, spinal anesthesia, and infiltration anesthesia.

The mechanism of action of tetracaine involves the reversible blockade of sodium channels on the neuronal cell membrane. By preventing sodium ion influx during depolarization, tetracaine inhibits the generation and propagation of action potentials along nerves, resulting in loss of sensation in the targeted area. Its high potency and long duration are due to the ester structure, which is hydrolyzed slowly by plasma esterases compared to shorter-acting esters like procaine.

Tetracaine is primarily applied in ophthalmology for topical anesthesia of the eye, in otolaryngology for procedures involving the ear and throat, and in dermatology for minor surgical interventions. It is also used in combination with other anesthetics or vasoconstrictors to prolong its effect and reduce systemic absorption. Because it is an ester-type anesthetic, tetracaine is metabolized in the blood by pseudocholinesterase enzymes, which reduces systemic toxicity compared with amide-type local anesthetics.

In addition to medical applications, tetracaine has been utilized in research to study nerve conduction and electrophysiology. Its ability to selectively block nerve impulses allows scientists to investigate ion channel function and neuronal excitability.

Overall, tetracaine is a potent, long-acting local anesthetic with a benzene-derived ester structure that enables effective blockade of sodium channels. Its combination of lipophilic and hydrophilic features, along with slow metabolic degradation, makes it a widely used and reliable anesthetic in medical procedures requiring surface or regional anesthesia.

References

2025. Expert consensus on the prevention and treatment of radiochemotherapy-induced oral mucositis. International Journal of Oral Science.
DOI: 10.1038/s41368-025-00382-8

2025. Solid Lipid Nanoparticles: An Innovative Drug Delivery System for Enhanced Bioavailability and Targeted Therapy. AAPS PharmSciTech.
DOI: 10.1208/s12249-025-03185-6

2025. Rapid local anesthesia in children enhanced by STAR particles: a first-in-humans, randomized clinical trial. Drug Delivery and Translational Research.
DOI: 10.1007/s13346-025-01899-5