Freebase or free base refers to the pure basic form of an amine, as opposed to its salt form. The amine is usually an alkaloid natural product. Free base is commonly used in organic chemistry and pharmaceuticals to describe the unprotonated amine form of a compound.
Most alkaloids are unstable in their pure form and exist in ionic salt form. The salts usually exhibit greater water solubility. Common counterions include chloride, bromide, acetate and oxalate. Because of the ubiquity of chloride salts, formed from the reaction of the amine with hydrochloric acid, these amine derivatives are known as the hydrochlorides. For example, compare the free base hydroxylamine (NH2OH) with hydroxylamine hydrochloride (NH3OH+ Cl-).
The term "freebasing" means to convert an ionic form into free base. It can refer to deprotonating hydrochloride salt form of cocaine to free base form. The process provides for same merits of acid-base extraction. The free base is preferred for smoking because the evaporation point of the free base is further apart from the burning point compared to the hydrochloride salt, making the salt form more prone to destruction by pyrolysis. Some of the active drug is lost in the deprotonation process. Freebasing became popular in the United States during the 1980s, mainly due to the fear of diseases such as HIV and viral hepatitis, since users did not have to share hypodermic needles.[1]
Freebasing is also the consumption by smoking of free base cocaine, crack cocaine, or heroin.
"Freebasing" may also describe the use of ammonia in cigarettes, which helps convert bound nicotine molecules in tobacco smoke into free nicotine molecules, therefore, boosting the effect of the nicotine on the smoker.[2]