You might have heard of ketamine referred to as a party drug or a horse tranquiliser. It’s true that ketamine is commonly misused for recreational purposes and it also has legitimate uses in the veterinary field.
It was, though, developed for use as a human anaesthetic in the 1960s. It is still used for that purpose, as well as for the treatment of severe or chronic pain in certain circumstances. Ketamine is also increasingly being used as a therapeutic to help people who are experiencing mental health issues including treatment-resistant depression, anxiety, PTSD and alcohol addiction.
Understanding ketamine’s origin is important because patients and legitimate users need to have trust in the efficacy and safety of the drug. Street drugs can often vary in potency or be cut with other substances, whereas clinical ketamine is made to the most rigorous of standards.
What is Ketamine?
Ketamine is a dissociative anaesthetic that has some hallucinogenic effects. In more technical terms, it is an NMDA receptor antagonist, meaning it blocks the N-methyl-D-aspartate neurotransmitter in the brain. It can have a number of effects, including sedation, relaxation, pain relief and antidepressant effects.
Ketamine hydrochloride is a cyclohexane derivative closely related chemically and pharmacologically to the veterinary drug phencyclidine. Ketamine exists as its two enantiomers, S- (esketamine) and R- (arketamine). Enantiomers are pairs of molecules that are non-superimposable mirror images of each other, like a chemical version of left and right hands. These enantiomers possess distinct pharmacological and therapeutic properties.
Illegal or ‘street’ ketamine generally comes as a clear liquid or white or off-white crystalline powder. Clinical ketamine is usually liquid and can come in a variety of forms, including oral suspension, oral solution, solution for injection and spray.
Synthesis of Ketamine: Overview
The history of ketamine started in the 1950s as researchers investigated a drug group known as cyclohexylamines for an ‘ideal’ anaesthetic agent with analgesic properties. Unlike some drugs, ketamine is entirely synthetic, meaning it doesn’t occur naturally like opioids.
The clinical ketamine used today is made in the laboratory via rigorous and exacting chemical processes. It is a complex overall process but can be broken down into a number of key steps.
First the organic chemical compound cyclohexanone (which is also used to make nylon) goes through a series of chemical reactions, including a condensation reaction with hydroxylamine hydrochloride to make intermediate products needed to synthesise ketamine. These intermediate compounds are reduced and undergo purification techniques that may include distillation, recrystallisation and filtration, among others.
The goal is to produce incredibly pure ketamine hydrochloride that is free of any contaminants.
Crucially, the whole process involves exacting procedures carried out in a controlled and sterile laboratory environment. This allows for the safe and consistent production of ketamine for clinical use. Quality control checks are carried out at various stages, including checks of the raw material, monitoring of the chemical processes as they are carried out and testing the final product using advanced analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry.