Methylecgonidine coats the crack particle

• Published in: Pharmacology, biochemistry and behavior Vol. 53; no. 1; pp. 57 - 66
• Main Authors: Wood, Ronald W., Shojaie, Jalil, Fang, Ching Ping, Graefe, John F.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 1996; Elsevier Science
• Subjects: Administration, Inhalation; Aerosols; Biological and medical sciences; Cocaine; Cocaine - analogs & derivatives; Cocaine - chemistry; Crack; Crack Cocaine - chemistry; Drug addictions; Drug aerosols; Hot Temperature; Medical sciences; Methylecgonidine; Particle Size; Particle-size aerosol; Toxicology; Vapor pressure; Particle-size aerosol; Cocaine; Methylecgonidine; Vapor pressure; Crack; Drug aerosols; Pyrolysis; Metabolite; Psychotropic; Drug of abuse; Simulation model; Chemical properties; Physical properties; Inhalation
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(95)00198-0

Crack is a form of cocaine base self-administered by smoking. When heated, it volatilizes and may partially pyrolyze to methylecgonidine (MEG). Upon cooling, a condensation aerosol forms. Heating cocaine base in model crack pipes produced particles of about 1 μm in diameter, regardless of the amount heated; however, MEG concentration increased from ≤ 2% at 10 mg per heating to as much as 5% at 30 mg per heating. Methylecgon-idine was ≤ 1 % of the recovered material when cocaine was vaporized off a heated wire coil, but the particles were larger (2–5 μm), and the distribution disperse. The vapor pressure of MEG was higher [log P(mm Hg) = 9.994 − 3530/T] than cocaine base, consistent with MEG coating the droplet during condensation, and with evaporation during aging or dilution. Disappearance of MEG from a chamber filled with crack smoke was a two-component process, one proceeding at the rate of cocaine particle removal, and the other at the desorption rate from other surfaces. Particle diameter influences the deposition site in the respiratory tract; thus, the likely different patterns of deposition in the respiratory tract of humans and animals of crack aerosols produced by different techniques warrant consideration, as they may influence our understanding of immediate and delayed sequelae of the inhalation of cocaine and its pyrolysis product, MEG.