The percentages of DHMA conjugates to total DHMA and HMMA conjugates to total HMMA were calculated at each time point and were consistent among the 10 participants.
Urinary ratios of DHMA 3-sulfate/DHMA 4-sulfate were calculated at each time point.
Several studies have been performed to determine urinary excretion kinetics following controlled MDMA administration; in all, however, DHMA, HMMA, or HMA pharmacokinetic data were obtained after conjugate cleavage by either acid or enzymatic hydrolysis with Helix pomatia (22-25).
In this study, however, concentrations of free drugs were <5% of total DHMA and HMMA, which further indicates a sufficient stability of the phase II metabolites.
Because reference calibrators of the phase II metabolites were not commercially available and synthesis of these had to be performed in the authors' laboratory, quantification focused on the main phase II metabolites DHMA 3-sulfate, DHMA 4-sulfate, HMMA sulfate, and HMMA glucuronide.
max] values were observed after low and high doses for DHMA 3-sulfate, DHMA 4-sulfate, HMMA sulfate, and HMMA glucuronide.