Simultaneous quantification of cannabinoids tetrahydrocannabinol, cannabidiol and CB1 receptor antagonist in rat plasma: An application to characterize pharmacokinetics after passive cannabis smoke inhalation and co-administration of rimonabant

Abstract

A highly sensitive and selective liquid chromatography-tandem mass spectrometry method for the determination of tetrahydrocannabinol (THC), cannabidiol, and rimonabant in rat plasma was developed. Analytes and the internal standard were extracted from plasma using a combination of protein precipitation followed by liquid-liquid extraction. Chromatographic separation was done using Waters Symmetry C18, 4.6 × 150 mm, 5 um column using 10 mm ammonium formate buffer and methanol. The total run time was 6 min, and separation was achieved using isocratic elution at a flow rate of 1 mL/min using a 10:90 (aqueous: organic) ratio. The ionization of the analytes was optimized using electrospray ionization in positive mode, and multiple reaction mode was used for this analysis. This method showed linearity from 0.1 to 100 ng/ml for all the analytes and was validated according to FDA Bioanalytical Method Validation Guidance in terms of accuracy, precession, linearity, stability, matrix effect, recovery, and stability. This method was successfully applied to characterize the pharmacokinetics of THC in rats after continuous passive smoke exposure for 50 min when rimonabant was co-administered with cannabis smoke. Maximum concentration (C) for THC was observed immediately after rats were removed from the exposure chamber (10 min post completion) which declined with a terminal half-life of 3.7 h and clearance was calculated to be 1.1 (L/h). Rimonabant (i.p) at a dose of 3 mg/kg was rapidly absorbed and maximum concentration (Cmax) was seen at 11 min which declined with a terminal half-life of 5.4 h and clearance was calculated to be 2.0 (L/h). Exposure AUC (h* μg/L) for THC and rimonabant were 13.9 and 457.6 respectively. As this method was highly sensitive and required only 50 μL of plasma, it is applicable in rodent models that assess the exposure-response relationships of these drugs.

Enhancing effects of acute exposure to cannabis smoke on working memory performance

“…Blood levels of THC were not assessed in the rats used in the present study. In a separate study however, we showed that exposing rats to smoke from the 5 cigarette condition in the same apparatus produced plasma THC levels of approximately 10 ng/ml within minutes of removal from the smoke exposure chamber, as assessed by liquid chromatography-mass spectrometry (Ravula et al, 2018). Although this value is low compared to levels measured in humans following cannabis smoking [(and lower than values we reported previously with the same smoke exposure regimen as measured by ELISA; (Bruijnzeel et al 2016)], they are comparable to levels in rats 30 min after acute i.p.…”

A review on the recent advances in HPLC, UHPLC and UPLC analyses of naturally occurring cannabinoids (2010–2019)

“…Table presents the summary of all LC‐based analytical methods for the quantification of cannabinoids in various animal samples published during 2010–2019 . All those LC methods were HPLC‐based, and there has been no report on the use of UPLC for animal sample during this period.…”

“…Zgair et al . used a simple HPLC‐UV‐PDA based separation and detection of CBD ( 3 ) and THC ( 12 ), and most recently, Ravula et al . have applied ESI‐MS/MS on the ABSCIEX API 5500 QTrap mass spectrometer using the positive ion mode for the quantification of same cannabinoids present in rat plasma samples.…”

“…have applied ESI‐MS/MS on the ABSCIEX API 5500 QTrap mass spectrometer using the positive ion mode for the quantification of same cannabinoids present in rat plasma samples. The latter method was designed to investigate pharmacokinetics aspects of cannabinoids after passive cannabis smoke inhalation, and offered effective the quantification of CBD ( 3 ) and THC ( 12 ) at concentrations up to 0.1 ng/mL, which could provide better understanding of the elimination phase of these compounds. This method required only 50 μL for processing, which could be considered useful for repeated sampling regimens in small animals such as rodents, making this method cost effective, and suitable for the detection of the analytes over extended periods.…”

New UHPLC Method for Cannabidiol Determination in Hard Capsules

“…There are few literature data regarding CBD determination in formulations. Ravula A et al proposed a similar method in terms of efficiency and analytical performances [14], but in comparison with the method published by Zgair A et al with a retention time about 8.3 minutes, the current method is closed to a high-throughput one [15].…”