Benzocaine, a.k.a. 4-aminobenzoic acid ethyl ester, is a local anaesthetic commonly used as a topical pain reliever. It is the active ingredient in many over-the-counter analgesic ointments.

Chemical properties

Benzocaine is an ester, a compound made from the organic acid PABA (para amino benzoic acid) and ethanol. The process in which this ester is created is known as Fischer esterification.

Related products

There are various other products that are also made from esters of PABA, many of which have similar anaesthetic properties. Dentists use Procaine (also called Novocaine) to numb teeth and gums.

How it relieves pain

Pain is caused by the stimulation of nerve endings. When the nerve endings are stimulated, sodium is enters the nerve ending, which causes an electrical signal to build up in the nerve. Once the electric signal becomes big enough, it is able to travel to the brain, which then interprets this as pain.

Esters of PABA works as a chemical barrier, stopping the sodium from being able to enter the nerve ending.

Products that contain Benzocaine

• First aid creams
• Sore-throat spray
• Sunburn remedies

See also

• Cocaine
• Novocaine