New CBD Formulation Achieved Higher Blood Levels Than Epidiolex in Rats
A biodegradable self-emulsifying CBD formulation outperformed the FDA-approved Epidiolex in oral bioavailability and peak plasma concentrations in animal testing.
Quick Facts
What This Study Found
Polyglycerol-based self-emulsifying drug delivery systems (SEDDS) achieved 3.8% absolute oral bioavailability for CBD compared to 3.4% for Epidiolex, with peak plasma concentrations of 30.6-35.8 ng/mL versus 25.0 ng/mL for Epidiolex.
Key Numbers
CBD payload: 20% w/w. CBD retention in lipid core: 92.95-93.54%. PG-based SEDDS bioavailability: 3.8% vs. Epidiolex 3.4%. Peak plasma CBD: 30.6-35.8 ng/mL (SEDDS) vs. 25.0 ng/mL (Epidiolex).
How They Did This
Three SEDDS formulations using different emulsifier types were developed and characterized through in vitro testing (surface properties, lipolysis, mucus permeation) and in vivo pharmacokinetic comparison with Epidiolex in rats.
Why This Research Matters
CBD has notoriously poor oral bioavailability, meaning most of what you swallow never reaches your bloodstream. Better formulations could make oral CBD more predictable and effective, which matters for both pharmaceutical and consumer products.
The Bigger Picture
While the bioavailability improvement over Epidiolex is modest, the use of PEG-free, biodegradable emulsifiers could address growing concerns about PEG-based ingredients. This line of research points toward CBD formulations that are both more effective and potentially safer for long-term oral use.
What This Study Doesn't Tell Us
Animal pharmacokinetics do not directly translate to humans. The bioavailability improvement over Epidiolex was modest. Long-term stability and real-world performance of the formulations were not assessed. Only single-dose PK was measured.
Questions This Raises
- ?Whether the PG-based SEDDS bioavailability advantage holds up in human trials
- ?How the formulation performs with repeated dosing over weeks or months
Trust & Context
- Key Stat:
- Evidence Grade:
- Well-characterized in vitro and in vivo work with appropriate comparator (Epidiolex), but animal data only and modest improvement in the primary outcome.
- Study Age:
- Published 2025.
- Original Title:
- Oral formulations for cannabidiol: Improved absolute oral bioavailability of biodegradable cannabidiol self-emulsifying drug delivery systems.
- Published In:
- Colloids and surfaces. B, Biointerfaces, 255, 114879 (2025)
- Authors:
- Sandmeier, Matthias, Wong, Ee Tsin, Nikolajsen, Gitte Nykjær, Purwanti, Asef, Lindner, Sera, Bernkop-Schnürch, Andreas, Xia, Wenhao, Hoeng, Julia, Kjær, Kathrine, Bruun, Heidi Ziegler, Jensen, Sanne Skov
- Database ID:
- RTHC-07566
Evidence Hierarchy
Frequently Asked Questions
Why is CBD bioavailability so low?
CBD is highly fat-soluble and undergoes extensive first-pass metabolism in the liver, meaning most oral CBD is broken down before reaching the bloodstream. Even the best formulations achieve single-digit bioavailability.
Is 3.8% vs. 3.4% bioavailability a meaningful difference?
On its own, the difference is small. The more notable finding is the higher peak plasma concentrations (up to 43% higher than Epidiolex), which could translate to better therapeutic effects at the same dose.
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Cite This Study
https://rethinkthc.com/research/RTHC-07566APA
Sandmeier, Matthias; Wong, Ee Tsin; Nikolajsen, Gitte Nykjær; Purwanti, Asef; Lindner, Sera; Bernkop-Schnürch, Andreas; Xia, Wenhao; Hoeng, Julia; Kjær, Kathrine; Bruun, Heidi Ziegler; Jensen, Sanne Skov. (2025). Oral formulations for cannabidiol: Improved absolute oral bioavailability of biodegradable cannabidiol self-emulsifying drug delivery systems.. Colloids and surfaces. B, Biointerfaces, 255, 114879. https://doi.org/10.1016/j.colsurfb.2025.114879
MLA
Sandmeier, Matthias, et al. "Oral formulations for cannabidiol: Improved absolute oral bioavailability of biodegradable cannabidiol self-emulsifying drug delivery systems.." Colloids and surfaces. B, 2025. https://doi.org/10.1016/j.colsurfb.2025.114879
RethinkTHC
RethinkTHC Research Database. "Oral formulations for cannabidiol: Improved absolute oral bi..." RTHC-07566. Retrieved from https://rethinkthc.com/research/sandmeier-2025-oral-formulations-for-cannabidiol
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.