Benzocaine

 

Benzocaine

Chemical formula	C9H11NO2
Molar Mass(g/mol)	165.189
Density(g/cc)	1.17
Melting Point(°C)	88-90
Boiling Point(°C)	310
NFPA 704	0 0 0

Benzocaine is included in DHS and is used to treat ear, eye, or oral pain. It is also combined with antipyrine to form A/B otic drops to relieve ear pain.

Uses

Primary

• Pharm: DHS AMF
• Precursor to procaine on the WHO LEM

Production

Synthesis

PABA

1. Combine 4-aminobenzoic acid with anydrous (100%) ethanol
2. Add sulfuric acid dropwise,
3. Esterify in warm reflux conditions producing benzocaine
4. Neutralize with sodium bicarbonate
5. Filter
6. Discard filtrate
7. Retain residue (benzocaine)

Preparations

• A 20-50% topical gel is often used for local anesthesia