Qingchen Zhang
University of Florida
Co-Authors: Philip W. Melchert1, Rodrigo Cristofoletti1
1University of Florida
Cannabidiol (CBD) is a medically used compound extracted from the cannabis plant. Epidiolex® CBD solution is the first FDA-approved therapeutic derived from cannabis indicated for the treatment of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome. Additional pharmacological activity has been attributed to CBD through in vitro research and clinical use, including anti-inflammatory and anti-oxidative effects. Current clinical research has identified a large degree of variability in CBD pharmacokinetics, but the source of this variability is not yet clear, especially with regard to long-term use of the cannabinoid.
We conducted a healthy volunteer drug-drug interaction study with CBD which permitted us the opportunity to further evaluate potential correlations between CBD pharmacokinetic profiles on the fourth day of administration and individual subjects\’ race, gender, age and weight. Twelve healthy subjects (six male and six female) were administered 75 mL of Epidiolex (750 mg CBD orally) twice daily for three days. The subjects were then admitted to a research unit on the fourth day, and their plasma was collected at nine time points over an 8 hour period after CBD administration in the morning. CBD concentrations were then determined by LC/MS-MS.
We analyzed the pharmacokinetic profile of CBD with non-compartmental analysis. In 12 subjects, the maximum plasma concentration (Cmax) is 389.17 ± 153.23 ng/mL (mean ± SD), the total area under the time-concentration curve (AUCtotal) is 1542.19 ± 488.04 ng/mL*hr (mean ± SD). We further compared the individual PK parameters grouped by age, gender, race and weight. Additionally, we will present a physiologically-based pharmacokinetics model to further characterize the sources of variability in CBD pharmacokinetic parameters.