Preparation of an anhydrous reverse micelle delivery system to enhance oral bioavailability and anti-diabetic efficacy of berberine

To enhance oral bioavailability and anti-diabetic efficacy of berberine (BER), an anhydrous reverse micelle (ARM) delivery system was prepared through lyophilization of water-in-oil (W/O) emulsions. Using soy phosphatidylcholine as emulsifiers, BER-containing W/O emulsions were prepared and then lyophilized to form dry products which, upon addition of oil, formed clear ARMs containing amorphous BER nanoparticles. BER-loaded ARMs or free BER solutions were administered to streptozocin-induced diabetic mice. In vivo measurements demonstrated that the blood glucose levels (BGLs) of diabetic mice reduced on average to 22% of the initial values 4 h after intravenous injection of BER solution at the dose of 2.5 mg/kg body weight, while the average BGL reduction was 57% in the group gavaged with ARMs at the dose of 100 mg/kg body weight. No significant BGL reduction was noticed in mice orally received BER solutions. Compared to BER solutions, the oral bioavailability of BER-loaded ARMs was enhanced 2.4-fold, and the maximum blood concentration of BER was enhanced 2.1-fold with a 2-h time lag leading to a prolonged efficacy. Thus, this novel ARM delivery system provides a valid method to improve oral bioavailability and anti-diabetic efficacy of BER, offering a promising product alternative to other hypoglycemic drugs for diabetes therapy.

Graphical abstractThe controlled release of oily formulation anhydrous reverse micelles enhanced remarkably the bioavailability and hypoglycemic efficacy of berberine.Figure optionsDownload full-size imageDownload as PowerPoint slide