Limited pharmacokinetic and safety study with daily feeding of hemp pellets in domestic goats: cannabidiolic acid is absorbed and retained better than cannabidiol

Objective To determine serum pharmacokinetics and evaluate safety after oral cannabidiol (CBD)/cannabidiolic acid (CBDA)-rich hemp pellets administrated to goats. Methods Eight 7-year-old female goats received 3 mg/kg CBD and 2 mg/kg CBDA from hemp pellets daily for 14 days. Serum samples were collected at 0, 0.5, 1, 2, 4, 8, 12, and 24 hours and at 7 and 14 days, from September through November of 2023. Serum concentrations for 12 cannabinoid/metabolites were determined using LC-MS. Pharmacokinetic parameters were calculated using noncompartmental analysis. Chemistry panels and CBCs were performed before administration and after 14 doses. Results Only CBDA was measurable within the first 24 hours. The maximum geometric mean serum concentration was 30.0 ng/mL (range, 21.3 to 59.2 mg/mL), the median time of maximum serum concentration was 18 hours (range, 4 to 24 hours), and the geometric mean area under the plasma concentration-versus-time curve was 410.2 ng·h/mL (range, 174.4 to 919.3 ng·h/mL). Mean ± SD serum concentrations 6 hours after administration on days 7 and 14 were 2.2 ng/mL ± 1.8 and 1.7 ng/mL, respectively, for CBD, and they were 52.4 ± 19.7 ng/mL and 53.0 ± 16.6 ng/mL, respectively, for CBDA. Conclusions The absorption of CBDA was markedly higher than other cannabinoids, with no differences between days 7 and 14, suggesting stable serum concentrations within 7 days. Clinical Relevance Goats absorb CBDA from the rumen, and 3 mg/kg CBDA every 24 hours reaches similar serum concentrations to monogastric species. Due to low serum CBD concentrations and rapid metabolism, CBDA might be a preferable alternative to CBD in ruminant species.