Determination of ajulemic acid and its glucuronide in human plasma by gas chromatography-mass spectrometry.
A method using gas chromatography-mass spectrometry (GC-MS) and solid-phase extraction (SPE) was developed for the determination of ajulemic acid (AJA), a non-psychoactive synthetic cannabinoid with interesting therapeutic potential, in human plasma. When using two calibration graphs, the assay linearity ranged from 10 to 750 ng/ml, and 750 to 3000 ng/ml AJA. The intra- and inter-day precision (R.S.D., %), assessed across the linear ranges of the assay, was between 1.5 and 7.0, and 3.6 and 7.9, respectively. The limit of quantitation (LOQ) was 10 ng/ml. The amount of AJA glucuronide was determined by calculating the difference in the AJA concentration before ("free AJA") and after enzymatic hydrolysis ("total AJA"). The present method was used within a clinical study on 21 patients suffering from neuropathic pain with hyperalgesia and allodynia. For example, plasma levels of 599.4+/-37.2 ng/ml (mean+/-R.S.D., n=9) AJA were obtained for samples taken 2 h after the administration of an oral dose of 20 mg AJA. The mean AJA glucuronide concentration at 2h was 63.8+/-127.9 ng/ml.
Batista
Catarina
C
Laboratory for Phytopharmacology, Bioanalytics and Pharmacokinetics, Department of Clinical Research, University of Bern, Murtenstrasse 35, CH-3010 Bern, Switzerland.
Berisha
Myftar
M
Karst
Matthias
M
Salim
Kahlid
K
Schneider
Udo
U
Brenneisen
Rudolf
R
D000328:Adult; D000368:Aged; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D004355:Drug Stability; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D020719:Glucuronides / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000188:drug therapy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D020719:Glucuronides; D013759:Dronabinol; C471849:lenabasum