Benzocaine

• CAT Number: A000874
• CAS Number: 94-09-7
• Molecular Formula: C9H11NO2
• Molecular Weight: 165.2
• Purity: ≥95%
• Synonyms: Ethyl 4-aminobenzoate; Ethyl aminobenzoate; Ethyl p-aminobenzoate.
• Target: Anti-infection
• Storage: 2-8°C
• IUPAC Name: ethyl 4-aminobenzoate
• InChI: InChI=1S/C9H11NO2/c1-2-12-9(11)7-3-5-8(10)6-4-7/h3-6H,2,10H2,1H3
• InChIKey: BLFLLBZGZJTVJG-UHFFFAOYSA-N
• SMILES: CCOC(=O)C1=CC=C(C=C1)N

Benzocaine（Cat No.:A000874）, is a local anesthetic commonly used to temporarily numb or relieve pain on the skin and mucous membranes. It belongs to the class of ester-type local anesthetics and works by blocking nerve signals. Benzocaine is often found in over-the-counter products like topical creams, gels, and sprays, providing relief for conditions such as minor burns, insect bites, and sore throat. However, due to potential adverse reactions and misuse risks, its application should be by recommended guidelines. Its numbing effect and suitability for topical use make benzocaine a widely used analgesic agent.

Overview of Clinical Research

Originator: McNeil AB
Class: Aminobenzoic acids; Benzoates; Local anaesthetics; Small molecules
Mechanism of Action: Sodium channel antagonists
Orphan Drug Status: No
New Molecular Entity: No

Reference

[1]. Mini Rev Med Chem. 2020;20(1):3-11. doi: 10.2174/1389557519666190913145423.
Benzocaine: Review on a Drug with Unfold Potential.
Khair-Ul-Bariyah S(1)(2), Arshad M(1), Ali M(3), Din MI(1), Sharif A(1), Ahmed E(1).
Author information: (1)Institute of Chemistry, University of the Punjab, New Campus, Lahore-54590, Pakistan. (2)Department of Chemistry, Forman Christian College (A Chartered University), Lahore, Pakistan. (3)Natural & Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman.
Benzocaine is well-known for its role as an anesthetic agent and largely used in oral ulcers, ear pain and dental complications. Along with lidocaine and other local anesthetics, benzocaine has marked it as an anesthetic agent in surgical procedures and as Na+ channels blocker, as well. Analogues of benzocaine have been found to possess biological potentials including antibacterial, antifungal and anti-cancer. Some derivatives were found to have conspicuous action against tuberculosis. The current review focuses to explore the century-long potential of the molecule and its analogs that have appeared in the literature. Furthermore, highlighting the biological potential of benzocaine and its analogues shall open-up new dimensions of future research to design more potent analogues.
DOI: 10.2174/1389557519666190913145423 PMID: 31518221

[2]. Am J Ther. 2018 Nov/Dec;25(6):e771-e772. doi: 10.1097/MJT.0000000000000782.
Benzocaine-Associated Methemoglobinemia.
Khanal S(1), Modi R(2), Akhtar K(1), Ghimire A(2).
Author information: (1)Internal Medicine, State University of New York Upstate Medical University Syracuse, NY. (2)Department of Medicine, Pulmonary and Critical Care, State University of New York Upstate Medical University Syracuse, NY.
DOI: 10.1097/MJT.0000000000000782 PMID: 29912717

[3]. J Emerg Med. 2017 Dec;53(6):912-913. doi: 10.1016/j.jemermed.2017.09.004. Epub 2017 Nov 6.
Benzocaine-Induced Methemoglobinemia.
Kaufman MR(1), Aouad RK(1).
Author information: (1)Department of Otolaryngology, Head and Neck Surgery, University of Kentucky, Lexington, Kentucky.
DOI: 10.1016/j.jemermed.2017.09.004 PMID: 29102098

[4]. Molecules. 2018 Jul 16;23(7):1737. doi: 10.3390/molecules23071737.
The Analysis of the Physicochemical Properties of Benzocaine Polymorphs.
Paczkowska M(1), Wiergowska G(2)(3), Miklaszewski A(4), Krause A(5), Mroczkowka M(6), Zalewski P(7), Cielecka-Piontek J(8).
Author information: (1)Department of Pharmacognosy, Faculty of Pharmacy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. . (2)Department of Pharmacognosy, Faculty of Pharmacy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. . (3)Pozlab sp.z.o.o., 60-775 Poznan, Poland. . (4)Institute of Materials Science and Engineering, Poznan University of Technology, 60-965 Poznan, Poland. . (5)Pozlab sp.z.o.o., 60-775 Poznan, Poland. . (6)Department of Pharmacognosy, Faculty of Pharmacy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. . (7)Department of Pharmacognosy, Faculty of Pharmacy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. . (8)Department of Pharmacognosy, Faculty of Pharmacy, Poznan University of Medical Sciences, 60-781 Poznan, Poland. .
The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the solubility of selected polymorphs of benzocaine on their permeability through artificial biological membranes (PAMPA system) was evaluated. The polymorphs of benzocaine were obtained by means of techniques commonly used for the preparation of various pharmaceutical dosage forms: ball milling, micro milling, and cryogenic grinding, which allowed for the appearance or preservation of form III, the initial conformation of benzocaine. Ball milling resulted in the conversion of form III to I, whereas micro milling yielded form II. As a result of cryogenic grinding, form III of benzocaine was preserved. The identification of all polymorphic forms of benzocaine was confirmed via X-ray powder diffraction (PXRD) supported by FT-IR spectroscopy coupled with density functional theory (DFT) calculations. The differences in solubility, dissolution, and permeability through artificial biological membranes resulting from the polymorphic forms of benzocaine were established by using chromatographic determinations. Accelerated stability tests indicated that all polymorphic forms were chemically stable at a required level.
DOI: 10.3390/molecules23071737 PMCID: PMC6099396 PMID: 30013003

[5]. Anesth Prog. 2019 Spring;66(1):24-29. doi: 10.2344/anpr-66-01-01.
Efficacy of Topical Benzocaine in Maxilla: A Randomized Controlled Trial.
Rehman N(1), Qazi SR(2).
Author information: (1)Institute of Dentistry, CMH Lahore Medical College. (2)Oral and Maxillofacial Surgeon, Lahore, Pakistan.
This study aims to compare the effect of topical anesthesia against the use of no topical agent on pain of needle penetration and local anesthesia deposition during buccal infiltration in anterior maxilla. In a randomized controlled trial, 100 adult participants were randomly allocated to the benzocaine group (received 20% benzocaine gel) and no benzocaine group (received no topical agent) prior to buccal infiltration in maxillary anterior teeth. A 27-gauge needle was used to deposit 2% lidocaine with 1:100,000 epinephrine. Pain of needle penetration and local anesthesia deposition was recorded separately using an 11-point Numeric Pain Rating Scale. Results showed that although 20% benzocaine significantly reduced pain on needle penetration during buccal infiltration in maxillary anterior teeth, the difference was small and the clinical significance is not clear. Topical anesthetic did not affect pain of local anesthetic deposition.
DOI: 10.2344/anpr-66-01-01 PMCID: PMC6424162 PMID: 30883233