Corn protein nanodelivery system improves CBD bioavailability: Study
The researchers loaded FZP with CBD to improve the stability of CBD and simulated gastrointestinal fluid release to assess bioavailability.
Results showed that FZP-CBD could protect most of the CBD from being released in the stomach and then control its release in the intestines, promote the absorption of CBD in the small intestine and increase the bioavailability of CBD.
“FZP-CBD could improve the utilization value of CBD and provide a new idea for the application of CBD,” wrote researchers from the China Academy of Chinese Medical Sciences in Beijing.
Therapeutic efficacy of CBD
CBD, the non-addictive extract from Cannabis sativa L., has been shown to have antiepileptic and anti-inflammatory effects, however, its effectiveness is limited by poor water solubility and low oral bioavailability of approximately 6%.
As the authors explained, many CBD products are ethanol or oil-based, but highly lipophilic drugs delivered orally have been shown to precipitate in the gastrointestinal (GI) tract and are difficult to be completely solubilized.
To improve the bioavailability and therapeutic efficacy of CBD, the researchers aimed to develop a safe dosage form for the delivery of CBD to reduce metabolic degradation and improve solubility.
Zein is a key storage protein in corn, notable for its high content of nonpolar amino acids and lack of charged or polar amino acids, making it insoluble in pure water and anhydrous alcohols, but soluble in 50% to 95% aqueous ethanol.
However, natural zein's strong hydrophobicity and rigid structure hinder its adaptability for drug delivery. Therefore the researchers aimed to enhance the natural stability and drug release control of the zein nanoparticles (NZP) by incorporating hydrochloric acid (HCl).
Improved CBD bioavailability
The researchers dispersed NZP in 90% ethanol to obtain a solution and then divided it into two groups. One group was left untreated and the other was adjusted to pH 2.0 with HCl to improve molecular flexibility.
Both groups of solutions were divided into three equal portions, and different amounts of CBD were added, respectively, to obtain zein alcohol solutions containing CBD with low, medium and high concentrations.
The authors then assessed morphology, particle size (PS), polydispersity index (PDI), Zeta potential (ZP), EE%, loading capacity (LC%), storage stability, and in vitro simulated gastrointestinal fluid release of all solutions.
The oral bioavailability of the two was also explored for comparison by in vivo experiments in rats.
Results showed that FZP enhanced the bioavailability of CBD by approximately 85%. The peak serum concentrations also increased across the three FZP-CBD concentrations but did not wildly differentiate from each other. However, in the low, medium and high CBD-concentrated solutions, bioavailability was improved by 135.9%, 114.9% and 169.6%, respectively.
"Flexible zein can be used as a potential carrier of the highly lipophilic drug CBD, which provides a new idea to achieve the controlled release of highly lipophilic drugs in the intestine and the application of CBD in pharmaceutics," the authors concluded.
Journal: Frontiers in Nutrition
doi: 10.3389/fnut.2024.1431620
“Enhanced oral bioavailability of cannabidiol by flexible zein nanoparticles: in vitro and pharmacokinetic studies.”
Authors: YingLan Nie et al.
