Pharmaceutical smokable heroin was developed for a clinical
trial on medical co-prescription of heroin and methadone.
This product, consisting of 75% w/w diacetylmorphine base
and 25% w/w caffeine anhydrate, was intended for use via
“chasing the dragon”, that is, inhalation after volatilization.
This procedure involves heating the powder mixture, which
may lead to formation of degradation products that could
subsequently be inhaled. We developed a method that used a
high-performance liquid chromatography system that was
compatible with photodiode-array detection and mass
spectrometric detection to separate diacetylmorphine- and
caffeine-related compounds in a wide polarity range for analysis
of the vapor. This method was used to analyze the contents of the
plastic drinking straws that were used by patients to inhale the
vapors from pharmaceutical heroin used via chasing the dragon,
which were considered to be representative of the vapors the
patients inhaled. They contained primarily unchanged
diacetylmorphine, its main metabolite 6-acetylmorphine, caffeine,
and some morphine. Several unidentified peaks were observed
in the straw chromatograms. Chemical structures were proposed
for nine degradation products: morphine derivatives with
different substitution patterns of the C3, C6, and/or N17
positions, which comprised 0.4–9.7% of the straw sample
residue weight. Activity and toxicity of most of these compounds
are unknown and require further investigation.