Crack is made from cocaine -- a powdered drug that is derived from the leaves of the coca plant, which grows primarily in South America. Although cocaine didn't gain notoriety in the United States until the 1980s, it has been in use for centuries. Many generations of South American Indians have chewed its leaves to give them strength and energy.
Cocaine was first isolated from coca leaves in the mid-1800s. Back then, it was used for medicinal purposes in drinks -- and yes, the legend is true: Coca-Cola did once contain cocaine. By the late 1800s, cocaine was also being used as an anesthetic and to prevent excess bleeding during surgery. By the following century, people began to realize that cocaine was an addictive narcotic, and non-medical use of the drug was made illegal with the passage of the Harrison Narcotics Tax Act in 1914.
The chemical formula of cocaine is C17H21NO4. See IPCS: Cocaine for a look at its chemical structure.
Cocaine as a drug is taken in one of three ways: It is snorted, injected or smoked. The snorted form, cocaine powder, is made by dissolving coca paste from the coca leaves in a mixture of hydrochloric acid and water. Potassium salt is added to the mixture to separate out undesired substances to be removed. Ammonia is then added to the remaining solution, and the solid powder cocaine separates out. To inject cocaine, the user mixes the powder with a small amount of water and uses a hypodermic needle to force the solution directly into a vein.
Cocaine powder forms the base of freebase cocaine. Freebase cocaine has a low melting point, so it can be smoked. It is made by dissolving powder cocaine in water and a strong alkaloid solution such as ammonia. Then, a highly flammable solvent like ether is added, and a solid cocaine base separates out from the solution.
Crack cocaine is an easier-to-manufacture form of freebase cocaine.