Benzocaine is a local anesthetic 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-aminobenzoic acid) and
ethanol.
The process in which this
ester is created is known as
Fischer esterification.
How it relieves pain
Pain is caused by the stimulation of nerve endings. When the nerve endings are stimulated, sodium enters the nerve ending, which causes an electrical signal to build up in the nerve. Once the electrical signal becomes big enough, it is able to travel to the brain, which then interprets this as pain.
Esters of
PABA work as a chemical barrier, stopping the sodium from being able to enter the nerve ending.
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.
Benzocaine is also contained in products such as:
- First aid creams
- Sore-throat spray
- Sore-throat drops w/ Menthol
- Sore-throat relief strips
- Sunburn remedies
- Condoms
Other uses
Benzocaine can also be used as a fish anesthetic. Due to its low solubility in water, stock solution can be made with ethanol (95%). 25g of benzocaine per 200ml ethanol will make a solution strong enough to knock saltwater fish out in 2-4 minutes. They will regain equilibrium after 10-15 minutes. Use 5ml stock solution per 1L of saltwater. Some benzocaine will
precipitate out of solution when added to the saltwater, so it is recommended to add the volume of stock solution you will be using to a separate container and mix it with some saltwater before adding it to the tank.
It is also used in certain condoms to prolong sex by numbing the penis.**
External links
Local anesthetics
Benzocain | Benzocaína | Benzocaïne | Benzocaïne