To determine the pharmacokinetics of a solution containing cannabidiol (CBD) and cannabidiolic acid (CBDA), administered orally in 2 single-dose studies (with and without food), in the domestic rabbit (Oryctolagus cuniculus).
6 healthy New Zealand White rabbits.
In phase 1, 6 rabbits were administered 15 mg/kg CBD with 16.4 mg/kg CBDA orally in hemp oil. In phase 2, 6 rabbits were administered the same dose orally in hemp oil followed by a food slurry. Blood samples were collected for 24 hours to determine the pharmacokinetics of CBD and CBDA. Quantification of plasma CBD and CBDA concentrations was determined using a validated liquid chromatography–mass spectrometry (LC-MS) assay. Pharmacokinetics were determined using noncompartmental analysis.
For CBD, the area under the curve extrapolated to infinity (AUC)0–∞ was 179.8 and 102 hours X ng/mL, the maximum plasma concentration (Cmax) was 30.4 and 15 ng/mL, the time to Cmax (tmax) was 3.78 and 3.25 hours, and the terminal half-life (t1/2λ) was 7.12 and 3.8 hours in phase 1 and phase 2, respectively. For CBDA, the AUC0–∞ was 12,286 and 6,176 hours X ng/mL, Cmax was 2,573 and 1,196 ng/mL, tmax was 1.07 and 1.12 hours, and t1/2λ was 3.26 and 3.49 hours in phase 1 and phase 2, respectively. Adverse effects were not observed in any rabbit.
CBD and CBDA reached a greater Cmax and had a longer t1/2λ in phase 1 (without food) compared with phase 2 (with food). CBDA reached a greater Cmax but had a shorter t1/2λ than CBD both in phase 1 and phase 2. These data may be useful in determining appropriate dosing of cannabinoids in the domestic rabbit.
To determine severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) serum antibody titers in domestic goats after SC and IM administration of an experimental, veterinary SARS-CoV-2 vaccine.
31 healthy adult domestic goats from 4 zoological institutions.
On day 0, blood was collected for baseline serum titer before vaccination with 1 mL SARS-CoV-2 recombinant S protein vaccine SC (n = 22) or IM (n = 9). A booster vaccination was administered 21 (SC group) or 28 days (IM group) after the initial vaccine and blood samples were collected at days 21 (SC group) or 28 (IM group), 42, 90, and 180 postvaccinations. The study took place between September 27, 2021, and June 01, 2022. Seroconversion for SARS-CoV-2 was assessed by a SARS-CoV-2 virus neutralization (VN) assay.
Before vaccination, no goats had detectable antibodies. On day 42, 100% of goats had detectable serum titers. Serum titers peaked at day 42 for 94% of goats vaccinated by either route of administration. There was a significant difference between SC and IM groups regarding the proportion of goats with detectable titers on day 21/28 (68% vs 0%, respectively) and day 180 (50% vs 89%, respectively), relative to day 0.
The 2 vaccination protocols (SC 21 days apart and IM 28 days apart) were similarly effective in mounting serum antibody response in goats. The SC route of administration appeared to have a more rapid onset of immunity, while the IM route may have produced a longer duration of immunity. These data may be useful in determining appropriate SARS-CoV-2 vaccination schedules in ruminants.