Non-linear plasma protein binding of cannabidiol

Area of Science:

• Pharmacology
• Drug Metabolism
• Materials Science

Background:

• Cannabidiol (CBD) exhibits high plasma protein binding, influencing its pharmacological activity.
• Variations in protein binding can alter unbound CBD concentrations and therapeutic effects.
• This study investigated the non-linear nature of CBD protein binding and potential interactions with tizoxanide.

Purpose of the Study:

• To determine if cannabidiol (CBD) plasma protein binding is concentration-dependent.
• To assess the potential for tizoxanide to alter CBD protein binding.
• To identify materials that may interact with CBD and affect its delivery.

Main Methods:

• Ultrafiltration technique was employed to evaluate CBD protein binding in human plasma.
• Samples were prepared with varying CBD concentrations, with and without tizoxanide.
• High-performance liquid chromatography (HPLC) was used for analysis after micropartition.

Main Results:

• Cannabidiol demonstrated binding to borosilicate glass (9%) and polyethylene plastics (15%).
• The unbound fraction of CBD was approximately 2-fold higher at high concentrations compared to low concentrations, indicating non-linear binding.
• No significant binding interaction was observed between CBD and tizoxanide, with the unbound fraction remaining at 5% in both scenarios.

Conclusions:

• Cannabidiol (CBD) plasma protein binding is non-linear at higher concentrations, impacting drug elimination and efficacy.
• Borosilicate and polyethylene materials should be avoided in the formulation, packaging, and administration of CBD products.
• Co-administration of CBD medications with tizoxanide is considered safe, as no drug interaction affecting binding was detected.