# A Preliminary Pharmacokinetic Comparison of Δ-9 Tetrahydrocannabinol and Cannabidiol Extract Versus Oromucosal Spray in Healthy Men and Women

> **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637)
> **Publisher:** CED Clinic (https://cedclinic.com)
> **Canonical URL:** https://cedclinic.com/research/thc-for-biological-availability-randomized-controlled-trial/
> **Published:** 2026-09-29T22:28:54-04:00 | **Last Modified / Clinically Audited:** 2026-09-29T22:30:02-04:00
> **Clinical Summary:** Clinicians should consider the route of administration when prescribing THC:CBD formulations, as bioavailability may vary significantly between methods.

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Aim: Few studies have directly compared the bioavailability of different cannabinoid formulations. Our goal was to assess the pharmacokinetic parameters and relative bioavailability of two Δ9-tetrahydrocannabinol: cannabidiol (THC:CBD) formulations: orally administered THC:CBD extract and oromucosally administered nabiximols. Methods: This pilot crossover study counterbalanced (1) 1 mL of orally administered THC:CBD extract (10 mg/mL each of THC and CBD in grapeseed oil) and (2) oromucosally administered nabiximols (four sprays of 2.7 mg THC and 2.5 mg CBD per spray, for a total dose of 10.8 mg THC and 10 mg CBD). Blood samples were obtained pre-dose and at 16 post-dose timepoints over 24 h. Pharmacokinetic parameters were calculated for THC, 11-hydroxy-tetrahydrocannabinol (11-OH-THC), and CBD. Results: Twelve occasional cannabis users (6 male, 6 female) were tested under fasting conditions. Cmax for THC and CBD was significantly higher with significantly shorter half-lives for THC:CBD extract versus nabiximols. Cmax for nabiximols was significantly higher in males compared with females. Under both treatment conditions, THC and CBD were undetectable by 24 h post-dose, and 11-OH-THC was markedly reduced from its peak. No serious adverse events were reported. Conclusions: Little is known about the comparative pharmacokinetics of commercially available cannabis products. This pilot study shows that the extract formulation achieved higher THC and CBD concentrations within a shorter time frame than nabiximols. These findings may have implications for clinical populations using these formulations therapeutically. Future studies should examine multiple doses in the context of therapeutic outcomes to characterize the relative clinical utility of these formulations.

 

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### Verification & Medical Governance

- **Lead Clinical Author:** Benjamin Caplan, MD
- **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House).
- **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`).
- **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/).
- **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637).
- **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).